Affirmed by unpublished PER CURIAM opinion.

OPINION

The bankruptcy court imposed sanctions in this adversary proceeding against Bar-dyl Tirana, counsel for the debtor, Community Management Corporation of Maryland (“CMC”), under Bankruptcy Rule 9011 for filing and pursuing this proceed *809 ing against Benjamin Weitz and partnerships in which he had an interest (collectively, “Weitz”). On appeal, the district court reversed by an order dated October 11, 2002, and we now affirm that order.

Prior to bankruptcy, in 1991, Weitz sold his ownership interest in CMC to two former employees of CMC by means of a complex transaction involving a promissory note and collateralization of the note with the stock of CMC. When payment under the note became in default, the parties instituted multiple litigations in Maryland and in Virginia, each involving claims and counterclaims.

In February 2000, CMC filed a petition in bankruptcy under Chapter 11, and thereafter the trustee hired Bardyl Tirana, who had represented CMC in its other litigation against Weitz, to represent CMC’s interests in bankruptcy-related litigation. Tirana filed this adversary action on behalf of CMC, which Weitz alleged was the fourth suit in which CMC asserted the same or similar claims. On Weitz’ motion, the bankruptcy court dismissed most of CMC’s claims on the ground that they were barred by res judicata and collateral estoppel and imposed sanctions against Tirana in the amount of $33,000 because Tirana filed the complaint “in the face of a clear bar based upon the doctrines of res judicata or collateral estop-pel.” The bankruptcy court rejected Weitz’ alternative ground for sanctions based on the argument that the claims were barred by the Colorado River doctrine. See Colorado River Water Conservation District v. United States, 424 U.S. 800, 96 S.Ct. 1236, 47 L.Ed.2d 483 (1976). The bankruptcy court concluded:

Defendant’s reliance upon the Colorado River doctrine in support of this motion is inappropriate. The doctrine is a type of abstention that is discretionary. Therefore, this court will not consider the application of the Colorado River doctrine as a basis for the imposition of sanctions.

(Citations omitted).

On appeal to the district court, the district court reversed the bankruptcy court’s imposition of sanctions, concluding that CMC’s claims were not clearly barred by res judicata and collateral estoppel. Having not been presented with the alternative argument under the Colorado River doctrine, it did not review the bankruptcy court’s ruling on that doctrine.

In this appeal, Weitz does not challenge the district court’s ruling that CMC’s claims were not clearly barred by res judi-cata and collateral estoppel. Instead, he relies on the alternative ground presented to the bankruptcy court that CMC’s claims against Weitz were barred under the Colorado River doctrine.

Without resolving the complex question of whether the bankruptcy court’s ruling on the Colorado River doctrine is before us, see Sobering Corp. v. Illinois Antibiotics Co., 89 F.3d 357, 358 (7th Cir. 1996); Crocker v. Piedmont Aviation, Inc., 49 F.3d 735, 741 (D.C.Cir. 1995), we conclude that the bankruptcy court did not abuse its discretion in rejecting Weitz’ alternative argument that sanctions should be imposed because the claims were barred by the Colorado River doctrine.

Under the Colorado River doctrine, a federal court may, in rare cases, abstain from exercising jurisdiction over a federal action when a parallel state suit exists. 424 U.S. at 818-19, 96 S.Ct. 1236. Abstention, however, is “the exception rather than the rule,” with the balance of factors “heavily weighted in favor of the exercise of [federal] jurisdiction.” Al-Abood v. El-Shamari, 217 F.3d 225, 232 (4th Cir. 2000) (citation and internal quotation marks omitted). Weitz contends that sanctions *810 were warranted because Tirana filed dupli-cative pleadings and should have known that the bankruptcy court would invoke the Colorado River doctrine and refuse to exercise jurisdiction. However, given the discretionary nature of the Colorado River doctrine and the heavy presumption in favor of the exercise of jurisdiction, application of the doctrine would rarely, if ever, be so certain as to warrant sanctions for the filing of a parallel action in federal court. Certainly, the bankruptcy court did not abuse its discretion in rejecting this ground for sanctions.

Accordingly, we affirm the October 11, 2002 order of the district court denying sanctions.

AFFIRMED.