Hellenic Petroleum LLC v. Mansfield Oil Company of Gainsville, Inc., 1:19-cv-01071-DAD-SKO

Hellenic Petroleum LLC sued Mansfield Oil and another defendant in Aug. 2019; Mansfield filed counterclaims and an amended counterclaim.
Parties executed a July 10, 2020 Settlement: Hellenic to pay $950,000 over three years; settlement provided that on Hellenic’s default the court would enter judgment for $1,200,000 minus any payments made and Hellenic waived challenges to that judgment.
On July 15, 2020 the parties stipulated to dismiss the case without prejudice; the magistrate judge entered the dismissal and declined to retain jurisdiction to enforce the settlement.
After an October 29, 2021 addendum modifying the payment schedule, Hellenic stopped making payments after Nov. 19, 2021; Mansfield contends $275,085.23 was paid and seeks judgment for $924,914.77.
Mansfield moved (Jan. 12, 2022) to reopen, set aside the dismissal, and enter final judgment; Hellenic did not oppose. The court found diversity jurisdiction and granted Mansfield’s motion, directing entry of judgment for $924,914.77 and closing the case.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether the court retained ancillary jurisdiction to enforce the settlement after the dismissal	Dismissal without a reservation by the court means no ancillary jurisdiction (implicit)	N/A (court record shows magistrate declined to retain jurisdiction)	Court: No ancillary jurisdiction because dismissal did not reserve or incorporate settlement
Whether the court has an independent basis for jurisdiction (diversity) to enforce the settlement	Hellenic did not respond; no opposing jurisdictional facts presented	Mansfield: parties are diverse (GA corp v. FL LLC) and amount in controversy exceeds $75,000	Court: Diversity exists here; independent basis for jurisdiction over the enforcement motion
Whether the court should reopen the case, set aside dismissal, and enter judgment under the settlement terms	Hellenic did not oppose; no facts disputing default or amounts paid	Mansfield: settlement requires entry of $1.2M judgment on default less payments; requests $924,914.77	Court: Exercising discretion, granted reopening and entered final judgment for $924,914.77
Whether post-judgment interest should be awarded at 10% per annum	Hellenic did not respond	Mansfield requested post-judgment interest at 10% per annum	Court: Declined to award post-judgment interest because the settlement did not provide for it and no authority was shown

Kokkonen v. Guardian Life Ins. Co. of Am., 511 U.S. 375 (1994) (district court lacks ancillary jurisdiction to enforce a settlement unless dismissal reserves jurisdiction or settlement is incorporated into the order)
O'Connor v. Colvin, 70 F.3d 530 (9th Cir. 1995) (after dismissal federal jurisdiction terminates; enforcement of settlement requires independent basis for jurisdiction)
Ahanachian v. Xenon Pictures, Inc., 624 F.3d 1253 (9th Cir. 2010) (district courts have broad discretion in case management, including whether to reopen cases)
Keeling v. Sheet Metal Workers Int'l Ass'n, Local Union 162, 937 F.2d 408 (9th Cir. 1991) (review of vacating dismissal is for abuse of discretion)