ORIGINAL PROCEEDING PETITION FOR WRIT OF MANDAMUS
ROSENBERG, Justice.OPINION
In this original proceeding, relators seek a writ of mandamus directing the trial *633court to vacate an order reinstating a cause dismissed for want of prosecution. Rela-tors contend that the trial court signed the order of reinstatement after its plenary jurisdiction had expired and, therefore, that the order of reinstatement was void. We disagree, and, accordingly, we deny rela-tors’ petition for writ of mandamus.
Real-parties-in-interest William Max Schmidt, an employee of Continental Airlines, and his wife, Jo Ann Curry Schmidt, sued relators Eduardo Macarangal and Metro Airlines, Inc. The Schmidts sought recovery for injuries resulting from an on-the-job accident involving William Schmidt. National Union Fire Insurance Company of Pittsburgh, Pennsylvania, intervened in the suit. National Union asserted a subrogation claim for reimbursement of workers’ compensation benefits paid to Schmidt.
After Metro Airlines filed a notice of bankruptcy, the trial court, by letter, requested that the Schmidts’ attorney certify certain matters concerning the bankruptcy. The letter warned that failure to certify would result in dismissal for want of prosecution. After the Schmidts’ attorney failed to take the requested action, the trial court signed an order dismissing the cause for want of prosecution on December 31, 1991. Although the order’s caption listed National Union as an intervenor, the text of the order contained no explicit disposition of National Union’s claim. The order stated:
Plaintiff(s) having failed to take certain action heretofore specified by the court within the time period prescribed, the court finds that the cause should be dismissed for want of prosecution pursuant to TEXAS RULES OF CIVIL PROCEDURE 165a.
IT IS, THEREFORE, ORDERED, ADJUDGED and DECREED by the court that this cause be and is hereby dismissed and that all court costs shall be taxed against the Plaintiff(s), for which let execution issue.
IT IS FURTHER ORDERED that execution may issue in favor of the officers of the court against each party hereto respectively, for all costs by each incurred.
The Schmidts filed an unverified motion to reinstate on January 21, 1992, and an amended motion, which was verified, on February 14, 1992. The trial court reinstated the cause by order of March 2,1992.
In this original proceeding, relators seek a writ of mandamus directing the trial court to vacate the March 2, 1992 order. Relators contend that the Schmidts’ January 22, 1992 motion to reinstate did not extend the trial court’s plenary jurisdiction because it was not verified. Consequently, according to relators, the trial court signed the March 2nd order after its plenary jurisdiction had expired, and, therefore, the March 2nd order was void. The Schmidts respond that, because it contained no explicit disposition of National Union’s plea in intervention, the December 31st order was interlocutory. Since there was no final judgment, the Schmidts assert, the trial court retained jurisdiction to reinstate their suit in March.
I. THE TRIAL COURT’S JURISDICTION TO REINSTATE A CASE DISMISSED FOR WANT OF PROSECUTION
Rule 165a of the Texas Rules of Civil Procedure governs reinstatement of cases dismissed for want of prosecution. In such cases, a party may file a motion to reinstate within thirty days of the date on which the order of dismissal was signed. Tex.R.Civ.P. 165a(3). A timely motion to reinstate extends the trial court’s plenary jurisdiction in the same manner as a motion for new trial under rule 329b. See Tex. R.Civ.P. 329b. That is, it extends the trial court’s plenary jurisdiction until thirty days after the motion to reinstate is overruled. Tex.R.Civ.P. 165a(3).
Rule 165a requires the movant or his attorney to verify the motion to reinstate. Tex.R.Civ.P. 165a(3). An unverified motion to reinstate does not extend the trial court’s plenary jurisdiction. McConnell v. May, 800 S.W.2d 194, 194 (Tex.1990, orig. proceeding). In the absence of a verified motion to reinstate, the trial court’s plenary jurisdiction expires thirty days after the date on which it signed a final order of dismissal. Id. Mandamus is an appropriate remedy if the trial court grants an *634unverified motion after its plenary jurisdiction has expired. Id.
In this case, the Schmidts failed to file a verified motion to reinstate within thirty days of December 31, 1991, the date on which the trial court signed the order of dismissal, and the trial court reinstated the case more than thirty days after that date. Therefore, the determinative issue in this case is whether the December 31, 1991 order of dismissal was a final judgment. If the December 31st order was interlocutory, the trial court retained jurisdiction to reinstate the case on March 2nd, and rela-tors have failed to demonstrate that they are entitled to a writ of mandamus. See Massey v. Davis, 650 S.W.2d 551, 554 (Tex.App.-Eastland 1983, writ ref’d n.r.e.). On the other hand, if the December 31st order was a final judgment, then the trial court’s plenary jurisdiction expired on January 30, 1992, the March 2nd order of reinstatement is void, and relators are entitled to mandamus relief. McConnell, 800 S.W.2d at 194.
II. FINALITY OF THE DECEMBER 31, 1991 ORDER
To be final, a judgment must dispose of all issues and parties in a case. North East Indep. Sch. Dist. v. Aldridge, 400 S.W.2d 893, 895 (Tex.1966). The disposition need not always be express, however. In Aldridge, the Texas Supreme Court established a presumption of finality applicable to judgments signed in cases set for conventional trial on the merits. In such cases, the judgment’s failure to expressly dispose of one or more parties or claims does not preclude its being final. Instead, Aldridge instructs the reviewing court simply to presume that the trial court “intended to, and did, dispose of all parties legally before it and of all issues made by the pleadings between such parties.” Aldridge, 400 S.W.2d at 897-98. The Al-dridge court recognized an exception to this presumption of finality in cases where, as here, the plaintiff’s claim is dismissed for want of prosecution. In such cases, there is no presumption that the dismissal order also disposed of issues in an independent cross-action or counterclaim. Id. at 897; see also PHB, Inc. v. Goldsmith, 539 S.W.2d 60 (Tex.1976).
In this case, National Union asserted its subrogation claim by a plea in intervention. The caption of the December 31, 1991 dismissal order listed National Union as an intervenor, but the text contained no reference to National Union’s claim. Despite this failure to explicitly address National Union’s claim, relators would have us conclude that, even without benefit of the Aldridge presumption of finality, the December 31st order disposed of National Union’s claim. Relators present several somewhat interrelated arguments in support of their contention that the December 31st judgment is final.1 Relators argue that National Union’s claim is entirely derivative of the Schmidts’, so that when the trial court dismissed the Schmidts’ claim, by necessary implication it also disposed of National Union’s claim. In further support of their contention that the December 31st judgment is final, relators point out that the caption of the December 31st order listed National Union as a party; that the order dismissed “this cause”; and that the order provided for execution. These factors, according to relators, clearly show that the trial court intended to, and did, dispose of all parties and claims in the December 31st order. We disagree. A compensation carrier’s subrogation suit is governed by article 8308-4.05 of the Texas Workers’ Compensation Act. In general, if a covered employee sustains a work-related injury, a recovery of workers’ compensation benefits is the employee’s exclusive remedy against his employer. Tex.Rev.Civ.Stat.Ann. art. 8308-4.01 (Vernon Pamph. 1992). Article 8308-4.05, however, allows an injured employee to recover damages from a third-party tortfeasor. Tex.Rev.Civ.Stat.Ann. art. 8308-4.05(a) (Vernon Pamph. 1992). An employee who seeks damages *635from a third party remains entitled to pursue a claim for workers’ compensation benefits. Id. If the employee receives compensation benefits, however, the compensation carrier becomes subrogated to the rights of the employee and may enforce the liability of the third-party tortfeasor. Tex.Rev.Civ.Stat.Ann. art. 8308-4.05(b) (Vernon Pamph.Supp.1992).
This Court has interpreted the predecessor to article 8308-4.05 as creating only one cause of action against a third-party tort-feasor. Phennel v. Roach, 789 S.W.2d 612, 615 (Tex.App. — Dallas 1990, writ denied). The injured employee owns this cause of action, burdened by the right of the insurance carrier to recoup compensation paid. Id. Thus, this Court has held that, when the injured employee’s pleadings are stricken, the insurance carrier’s cause is also defeated. Id.
Despite the derivative nature of the carrier’s . subrogation claim, it is well established that article 8308-4.05(b) authorizes the carrier to bring suit against the third-party tortfeasor without joining the employee. See Watson v. Glens Falls Ins. Co., 505 S.W.2d 793, 796 (Tex.1974); Fort Worth Lloyds v. Haygood, 151 Tex. 149, 246 S.W.2d 865, 869 (1952). Thus, as the Schmidts observe, National Union could have asserted its subrogation claim against relators even in the absence of a suit by the Schmidts. The purpose of this subro-gation provision is to prevent overcompensation of the employee and to reduce the burden of insurance to the employer and to the public. American Gen. Fire & Cas. Co. v. McDonald, 796 S.W.2d 201, 204 (Tex.App. — San Antonio 1990, writ denied). Accordingly, the carrier’s right to reduce its liability through payments by a third party must not be compromised. Id.; see also Fort Worth Lloyds, 246 S.W.2d at 869-71 (when employee and third-party tortfeasor settle, first money recovered by the employee should go to reimburse the compensation carrier); Home Indem. Co. v. Thompson, 407 S.W.2d 530, 531 (Tex.Civ.App. — Texarkana 1966, no writ) (where employee and third party settle, both are liable to carrier for amount of compensation paid).
In this case, the December 31st order of dismissal is at best ambiguous in its treatment of National Union’s claim.2 Since the order is a dismissal for want of prosecution,3 there is no presumption that the trial court disposed of the subrogation claim. See Aldridge, 400 S.W.2d at 897; Davis v. McCray Refrigerator Sales Corp., 136 Tex. 296, 150 S.W.2d 377, 378 (1941) (“[Wjhere the court dismisses the plaintiff’s suit, and does not refer to or mention the defendant’s cross-action, the judgment does not dispose of the cross-action expressly or by implication, and is therefore not such a final judgment as will authorize an appeal therefrom.”). Neither the notice that precipitated the December 31st order of dismissal nor the order of dismissal expressly refers to National Union’s claim. In this context, the language dismissing “this cause” is not sufficient to dispose of National Union’s claim. See Legrand v. Niagara Fire Ins. Co., 743 S.W.2d 241, 242-43 (Tex.App. — Tyler 1987, no writ) (dismissal of “the above styled and numbered cause” did not dispose of defendant’s cross action); Massey, 650 S.W.2d at 554 (dismissal of “the hereinafter styled and numbered causes” did not dispose of interventions and cross-actions). The December 31st order does not expressly dispose of National Union’s claim. Further, since National Union could have asserted its claim *636in the absence of a suit by the Schmidts, we do not construe the December 31st dismissal as disposing of National Union’s claim by necessary implication. The December 31st dismissal order was interlocutory, and the trial court retained jurisdiction to reinstate the Schmidts’ claims in March. Accordingly, we deny relators’ petition for writ of mandamus.
BAKER, J., dissents and files an opinion.
. In their petition for writ of mandamus, rela-tors do not address whether the December 31st judgment is a final judgment despite its failure to dispose explicitly of National Union’s claim. Instead, they simply assume its finality. The arguments discussed in this opinion are the arguments that relators presented to the trial court in their response to the Schmidts’ amended motion to reinstate.
. This ambiguity distinguishes the present case from this Court’s opinion in Phennel v. Roach, 789 S.W.2d 612 (Tex.App. — Dallas 1990, writ denied). The opinion in Phennel suggests that the trial court’s order clearly disposed of both the injured employee’s and the compensation carrier’s suit. The issue addressed in Phennel was simply the correctness of that disposition. Phennel, 789 S.W.2d at 615.
. In summary judgments, another instance in which there is no presumption of finality, this Court has declined to construe ambiguous orders as final. See McClennahan v. First Gibraltar Bank, F.S.B., 791 S.W.2d 607 (Tex.App.— Dallas 1990, no writ); Sakser v. Fitze, 708 S.W.2d 40 (Tex.App. — Dallas 1986, no writ) (Mother Hubbard clause in summary judgment does not dispose of claims not presented in motion); but see Cockrell v. Central Sav. and Loan Ass’n, 788 S.W.2d 221 (Tex.App. — Dallas 1990, no writ).