               Not for Publication in West's Federal Reporter

          United States Court of Appeals
                      For the First Circuit

No. 09-2443

       JRA ARCHITECTS & PROJECT MANAGERS, P.S.C., ET AL.,

                      Plaintiffs, Appellees,

                                    v.

              FIRST FINANCIAL GROUP, INC., ET AL.,

                            Defendants,
                       _____________________

                       NILSA ORTÍZ-ALVARADO,

                       Defendant, Appellant.


          APPEAL FROM THE UNITED STATES DISTRICT COURT
                 FOR THE DISTRICT OF PUERTO RICO
        [Hon. Francisco A. Besosa, U.S. District Judge]


                                 Before

                   Lipez, Howard and Thompson,
                         Circuit Judges.



     Alfredo Castellanos, Dayra Amill-Acosta and Castellanos &
Castellanos Law Firm, P.S.C., on brief for appellant Nilsa Ortíz-
Alvarado.
     Jorge J. Oppenheimer-Méndez, Oppenheimer-Soltero Retirement
Plan Trust and Julie Soltero-Rinaldi on brief for appellees.




                             May 21, 2010
               Per Curiam. This appeal arises from the district court's

allowance of the plaintiffs' voluntary dismissal--without prejudice

and without any conditions--of the complaints in two consolidated

cases.    The sole appellant, Nilsa Ortíz-Alvarado ("Ortíz"), is a

defendant in both cases.

               Where, as here, a defendant has answered the complaint or

moved    for    summary   judgment,1   a     plaintiff   cannot   unilaterally

dismiss an action without court approval "on terms that the court

considers proper."        Fed. R. Civ. P. 41(a)(2).           The purpose of

requiring such approval is to ensure that "'no other party will be

prejudiced.'"       Doe v. Urohealth Sys., Inc., 216 F.3d 157, 160 (1st

Cir. 2000) (quoting P.R. Mar. Shipping Auth. v. Leith, 668 F.2d 46,

50 (1st Cir. 1981)).          Accordingly, in ruling on a motion for

voluntary dismissal, "[t]he district court is responsible . . . for

exercising its discretion to ensure that such prejudice will not

occur."    Id.

               In exercising that discretion, "courts typically look to

'the defendant's effort and expense of preparation for trial,

excessive delay and lack of diligence on the part of the plaintiff

in prosecuting the action, insufficient explanation for the need to

take a dismissal, and the fact that a motion for summary judgment

has been filed by the defendant.'"           Id. (quoting Pace v. S. Express



     1
      Ortíz filed an answer in both cases and a motion for summary
judgment in the JRA case.

                                       -2-
Co., 409 F.2d 331, 334 (7th Cir. 1969)).   Although "courts need not

analyze each factor or limit their consideration to these factors,"

id. (citing Tyco Labs., Inc. v. Koppers Co., 627 F.2d 54, 56 (7th

Cir. 1980)), they serve as "a guide for the trial judge, in whom

the discretion ultimately rests."     Tyco, 627 F.2d at 56.

          This court's review of a district court's approval of a

voluntary dismissal is for abuse of discretion,     Doe, 216 F.3d at

160, which can occur not only by failing to consider a significant

factor, relying on an improper factor, or making a serious mistake

in weighing the applicable factors, but also by failing to exercise

its discretion at all.   Janney Montgomery Scott LLC v. Tobin, 571

F.3d 162, 166 (1st Cir. 2009) (so holding with respect to a

discretionary award of attorneys' fees).       Where, as here, the

district court provides no explanation for dismissing a case

without prejudice and without imposing any conditions on the moving

party, such as paying the opposing party's attorneys' fees or

costs, and no reason for doing so is apparent from the record, this

court cannot assess whether an abuse of discretion has occurred.

Bridgeport Music, Inc. v. Universal-MCA Music Publ'g, Inc., 481

F.3d 926, 930-931 (6th Cir. 2007); Conafay by Conafay v. Wyeth

Labs., 793 F.2d 350, 354 (D.C. Cir. 1986).     Indeed, "the best we

can do [under those circumstances] is to conclude that the district

court abused its discretion by not exercising it,"      Janney, 571




                                -3-
F.3d at 166, and to remand for explicit consideration of the

appropriate factors, Urohealth, 216 F.3d at 163.

            If,    instead,     the    district       court     had      provided    "some

indication"       of   its   reasons      for      rejecting       Ortíz's     colorable

arguments for dismissing the case with, rather than without,

prejudice or for imposing conditions on the dismissal to ensure

that she is not unduly prejudiced by the dismissal, then remand

would not be required.          Bridgeport Music, 481 F.3d at 931; In re

Bayshore Ford Truck Sales, Inc., 471 F.3d 1233, 1259 (11th Cir.

2006).     Citing      relevant     factors--her           considerable      expense     in

actively defending the cases, the plaintiffs' relative lack of

diligence, the pendency of dispositive motions in both cases, and

the inadequacy of the plaintiffs' reasons for seeking dismissal--

Ortíz    argued    below     that   the      cases    should       be    dismissed     with

prejudice or with conditions, and she presses those arguments on

appeal.     Those      arguments      may,    or     may    not,    be    sound   in    the

circumstances of these cases, and other factors may weigh in favor

of dismissal without prejudice or conditions.                           But the district

court, which was actively involved in the management of these

complex cases, is in a better position to apply and weigh such

factors, at least in the first instance.

            The voluntary dismissals are vacated, and the case is

remanded to the district court for further proceedings. Each party

shall bear its own costs.


                                          -4-
