Spartan Concrete Prods., LLC v. Argos USVI, Corp., 929 F.3d 107

Spartan Concrete expanded from St. Croix into St. Thomas in 2010 and engaged in a multi-year price war with incumbent Heavy Materials, ultimately agreeing in 2013 to divide the islands (Spartan on St. Croix; Heavy Materials on St. Thomas).
Argos USVI was the sole bulk cement supplier on St. Thomas during the dispute and sold cement to both firms, giving Heavy Materials a 10% volume discount while not extending that discount to Spartan.
Spartan alleged Argos’ discount violated § 2(a) of the Robinson‑Patman Act and sued for antitrust damages, claiming the discount caused its losses and exit from St. Thomas.
At a bench trial the district court found Spartan proved discrimination but granted judgment for Argos on the ground Spartan failed to prove antitrust injury/damages; the court also denied Spartan leave to amend to add tort claims (intentional interference and civil conspiracy) because of undue delay and prejudice.
Spartan appealed both the judgment and denial of leave to amend; the Third Circuit affirmed, holding Spartan did not present competent evidence linking Argos’ discount to its actual losses and that the district court did not abuse its discretion in denying amendment.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Spartan proved antitrust injury/damages from Argos’ price discrimination under § 2(a) Robinson‑Patman and § 4 Clayton	Spartan: losses (over three years) and ultimate exit were caused by Argos’ exclusive 10% discount to Heavy Materials; price was decisive to customers	Argos: Spartan failed to show causal linkage; lost sales also resulted from Spartan’s own pricing strategy, quality competition, and bad debts; plaintiff offered only speculative testimony	Held: No antitrust injury proved—trial evidence lacked direct proof of lost customers or a reliable causal nexus; judgment for Argos affirmed
Whether district court abused discretion in denying leave to amend to add tort claims	Spartan: new documents produced during discovery revealed conspiracy/interference and amendment was timely after those productions; little prejudice to Argos	Argos/District Ct: parties (including Spartan) repeatedly missed discovery deadlines; amendment would cause undue delay and require new discovery, prejudicing Argos and the court	Held: No abuse of discretion—denial affirmed on independent grounds of undue delay and prejudice

Feesers, Inc. v. Michael Foods, Inc., 498 F.3d 206 (3d Cir. 2007) (elements of a § 2(a) Robinson‑Patman claim)
Stelwagon Mfg. Co. v. Tarmac Roofing Sys. Inc., 63 F.3d 1267 (3d Cir. 1995) (requirement that plaintiff show causal link between discriminatory pricing and lost sales for antitrust damages)
J. Truett Payne Co. v. Chrysler Motors Corp., 451 U.S. 557 (1981) (antitrust damages require proof of injury the antitrust laws were designed to prevent)
In re Lower Lake Erie Iron Ore Antitrust Litig., 998 F.2d 1144 (3d Cir. 1993) (relaxed proof on amount, not causation, of damages; need reasonable nexus between illegal act and injuries)
Cureton v. Nat’l Collegiate Athletic Ass’n, 252 F.3d 267 (3d Cir. 2001) (standard of review for denial of leave to amend)
Sabinsa Corp. v. Creative Compounds, LLC, 609 F.3d 175 (3d Cir. 2010) (when facts largely undisputed, appellate court need not remand for Rule 52(a) findings)
Arthur v. Maersk, Inc., 434 F.3d 196 (3d Cir. 2006) (undue delay can justify denial of leave to amend)
Rossi v. Standard Roofing, Inc., 156 F.3d 452 (3d Cir. 1998) (damages must not be speculative; need reasonable estimate)
EBC, Inc. v. Clark Bldg. Sys., Inc., 618 F.3d 253 (3d Cir. 2010) (bench‑trial standards and Rule 52(a) considerations)