This petition for review seeks to reverse the decision1 promulgated on August 27, 1999, of the Court of Appeals in CA-G! "# $o %1&7% The appellate court en'oined the enforcement of the writ of preliminar( in'unction dated April 1), 199*, issued +( the !egional Trial Court of ,alanga, ,ataan, ,ranch 1, in Civil Case $o --9% against private respondent, Antonio "antosThe factual antecedents of this case are as follows./n August 22, 19-9, the ,ureau of 0ands declared 1rancisco 2omingo, !e(naldo 1lorida, Cornelio #ilipino and "everino 3istan, lawful possessors of 0ot 1&79 of the 4orong, ,ataan Cadastre 0ot 1&79 consists of 1)) hectares 2omingo, 1lorida, #ilipino and 3istan through their fore+ears and +( themselves had +een in open, notorious, and e5clusive possession of portions of 0ot 1&79 since 19&& in the concept of owners The ,ureau then directed them to confirm their titles over the propert( +( filing the appropriate applications for the portions of the propert( respectivel( occupied +( them1wphi1.nt6n /cto+er 1977, petitioner +ought the respective portions of 2omingo, 1lorida, #ilipino and 3istan, totaling -9,9&2 s8uare meters and entered into a compromise settlement with si5 other persons occup(ing the propert(, whose applications had +een re'ected +( the ,ureau #etitioner then filed anapplication for land registration docketed as 0!C Cad !ec $o $-279 with the then Court of 1irst 6nstance of ,ataan, ,ranch 1 The application was contested +( several oppositors, among them theheirs of one Tori+io Ale'andro/n 2ecem+er 27, 1991, the trial court decided the land registration case in petitioner9s favor The losing parties appealed to the Court of Appeals, where the case was docketed as CA-G! C3 $o )7)%2 /n 4arch 1), 2777, the appellate court affirmed the lower court9s decision26n :une 1997, a group of occupants entered the land, destro(ed the fences and drove awa( livestockowned +( petitioner/n /cto+er 9, 1997, petitioner filed a complaint for in'unction with damages, with a pra(er for a temporar( restraining order, docketed as Civil Case $o --9%, with the !TC of ,alanga, ,ataan $amed as defendants were :uanito 6nfante, 2omingo 6nfante, 0ito 4angalidan, :aime A8uino, :ohn 2oe, #eter 2oe, and !ichard 2oeThe trial court issued the temporar( restraining order ;T!/< and on :anuar( 1-, 199*, the sheriff served copies on the defendants The sheriff accompanied petitioner9s president to the propert( where the( found five ;%< persons cultivating the land The latter refused to give their names or receive copies of the T!/ The( claimed that the( were onl( farm workers of a certain Antonio "antos who allegedl( owned the land&/n April 1), 199*, the trial court issued a writ of preliminar( in'unction restraining the defendants or persons acting on their +ehalf from entering and cultivating the disputed propert( The aforementioned writ was also served upon respondent who was occup(ing a portion of 0ot $o 1&79)/n 1e+ruar( 2), 1999, private respondent filed a special civil action for certiorari docketed as CA-G! "# $o %1&7% with the Court of Appeals #rivate respondent averred that he onl( learned a+outthe writ of preliminar( in'unction on 1e+ruar( 1-, 1999, when he secured a cop( of the order =e claimed that he was an innocent purchaser for value of the propert( from 1rancisco, Armando, and Conchita, all surnamed Ale'andro and the in'unction prevented him from using his propert( =e alleged that he was not a part( to Civil Case $o --9% and that it was grave a+use of discretion for the trial court to enforce the in'unctive writ against him since it did not have 'urisdiction over him/n August 27, 1999, the appellate court decided CA-G! "# $o %1&7% in private respondent9s favor, thus.>=?!?1/!?, premises considered the instant #etition is here+( G!A$T?2 #u+lic respondent is en'oined from imposing the 8uestioned writ of preliminar( in'unction dated April1), 199@*A against petitioner @"antosA"/ /!2?!?2%=ence, the instant petition, su+mitting the following issues for our consideration.A >=?T=?! @#!63AT?A !?"#/$2?$T >A" 2?#!63?2 /1 =6" C/$"T6TBT6/$A0 !6G=T T/ ,? =?A!2, >=?T=?! !B0? &, "?C 11 /1 T=? 1997 !B0?" /1 C6360 #!/C?2B!?- 6" A##06CA,0? 6$ T=? A,/3?-?$T6T0?2 CA"?>e find the lone issue to +e. 6s private respondent +ound +( the writ of preliminar( in'unction issued +( the trial courtCFirst, petitioner contends that the in'unctive writ of April 1), 199* was issued not onl( against all named defendants in Civil Case $o --9%, +ut also against three unnamed D2oesD 6t now argues that the D2oesD in the complaint are all those who violated its rights, including private respondent #etitioner asks us to note that the writ of in'unction was served not onl( against the defendants in Civil Case $o --9%, +ut also against other persons who were seen entering and cultivating petitioner9s propert(, including private respondent "ince the latter personall( received the in'unctive order on :une %, 199*, he was alread( forewarned to intervene in Civil Case $o --9% if he had an( right or interest to protect in the disputed propert( This he failed to do "ince private respondent did not then take the opportunit( to present his side, he cannot now claim that he was denied due process when the writ was enforced against him6n his comment, private respondent counters that he was not legall( +ound nor re8uired +( law to filehis pleadings in Civil Case $o --9% as he was not a part( in said case 0ikewise, he was not re8uired to act on or protest the in'unctive writ in the aforementioned civil case #rivate respondent avers that what petitioner wants is to have a continuing writ in its favor, to include not onl( the defendants in Civil Case $o --9% +ut also all those who ma( su+se8uentl( intrude into the land dispute #rivate respondent su+mits that the court a quo committed no error in descri+ing petitioner9sposture as a violation of the fundamental rights to notice and hearing>e have minutel( scrutiniEed the order granting the writ of preliminar( in'unction and are una+le to sa( that the writ applied to private respondent The order merel( stated D@0Aet a writ of preliminar( in'unction +e issued en'oining and restraining the defendants or an( person or persons acting in theirplace or stead from further entering and cultivating the said land of the plaintiff su+'ect matter of this case until further order from the CourtD7 The persons specificall( en'oined in the order were the defendants in Civil Case $o --9% or persons acting in their stead #etitioner itself admitted that private respondent was not a defendant in Civil Case $o --9% since Dat the institution of the case in 1997, he ;private respondent< did not have a right over an( portion of petitioner9s lotD* $either was he a trespasser then9 Also, nothing in the records indicate that private respondent was acting on +ehalf of an( of the defendants Taking all these into consideration, we must hold that the writ of preliminar( in'unction thus cannot +e made to appl( to private respondentA preliminar( in'unction is an order granted at an( stage of an action prior to final 'udgment, re8uiringa person to refrain from a particular act17 As an ancillar( or preventive remed(, a writ of preliminar( in'unction ma( therefore +e resorted to +( a part( to protect or preserve his rights and for no other purpose during the pendenc( of the principal action11 6ts o+'ect is to preserve the status quo until themerits of the case can +e heard12 6t is not a cause of action in itself +ut merel( a provisional remed(, an ad'unct to a main suit1& Thus, a person who is not a part( in the main suit, like private respondentin the instant case, cannot +e +ound +( an ancillar( writ, such as the writ of preliminar( in'unction issued against the defendants in Civil Case $o --9% =e cannot +e affected +( an( proceeding to which he is a stranger1)Second, petitioner contends that the Court of Appeals erred when it o+served that petitioner should have impleaded private respondent as defendant in Civil Case $o --9% pursuant to "ection 11, !ule & of the 1997 !ules of Civil #rocedure1% 6nstead, private respondent should have intervened in Civil Case $o --9% to protect his rights #etitioner avers that at the time the in'unctive writ was issued, it had alread( rested its case and to re8uire it to amend its complaint to include private respondent was too late#rivate respondent counters that there was no reason wh( "ection 11, !ule & of the 1997 !ules of Civil #rocedure should not +e made to appl( to Civil Case $o --9% =e argues that contrar( to petitioner9s posture, his inclusion as a defendant in Civil Case $o --9% is procedurall( correct since no final 'udgment had (et +een rendered in said case 4oreover, he avers that petitioner cannot insist that private respondent +e vigilant in protecting his rights +( intervening in Civil Case $o --9%1wphi1.nt>e agree with private respondent First, private respondent had no dut( to intervene in the proceedings in Civil Case $o --9% 6ntervention in an action is neither compulsor( nor mandator( +ut onl( optional and permissive1- Second, to warrant intervention, two re8uisites must concur. ;a< the movant has a legal interest in the matter in litigation,17 and ;+< intervention must not undul( dela( or pre'udice the ad'udication of the rights of the parties1* nor should the claim of the intervenor +e capa+le of +eing properl( decided in a separate proceeding19 The interest, which entitles a person tointervene in a suit, must involve the matter in litigation and of such direct and immediate character that the intervenor will either gain or lose +( the direct legal operation and effect of the 'udgment27 Civil Case $o --9% was an action for permanent in'unction and damages As a stranger to the case,private respondent had neither legal interest in a permanent in'unction nor an interest on the damages to +e imposed, if an(, in Civil Case $o --9% To allow him to intervene would have unnecessaril( complicated and prolonged the case>e agree with the Court of Appeals that to make the in'unctive writ applica+le against private respondent, petitioner should have impleaded the latter as an additional defendant in Civil Case $o --9% #etitioner9s insistence that it had rested its case and hence was too late to include defendant finds no support in "ection 11 The rule categoricall( provides that D#arties ma( +e dropped or added +( order of the court on motion of an( part( or on its own initiative at any stage of the action ;stress supplied< and on such terms as are 'ustD21 >e find it ine5plica+le wh( petitioner pointedl( resisted the advice of the appellate court to implead private respondent as an additional defendant inCivil Case $o --9%WHEREFORE, the instant petition is DENIED and the assailed decision of the Court of Appeals in CA-G! "# $o %1&7% AFFIRMED $o pronouncement as to costs