Feb 12 (Reuters) - Refiner PBF Energy PBF.N reported a surprise profit on Thursday, as supply disruptions tied to the Russia-Ukraine war and improved crude price differentials lifted refining margins.

PBF gained 49 cents per share on an adjusted basis in the fourth quarter, compared with estimates of a loss of 10 cents per share, according to data compiled by LSEG.

The U.S. refining industry saw a sharp recovery in the fourth quarter, with the 3-2-1 crack spread benchmark CL321-1=R rebounding from multi-year lows earlier in 2024. This turnaround was driven by tighter global fuel supplies and a seasonal uptick in demand, which bolstered profits.

The recovery follows a 2024 slump, when margins retreated from post-pandemic highs as supply disruptions linked to Russia's 2022 invasion of Ukraine eased.

"Oil markets remain dynamic, and many recent headwinds are now converting to tailwinds for refiners, particularly for PBF. Global refining capacity remains structurally constrained, with expected demand growth and rationalization outpacing new capacity additions," said CEO Matthew Lucey.

PBF Energy's consolidated gross refining margin, excluding special items, more than doubled to $11.16 per barrel in the fourth quarter.

The company's crude oil and feedstocks throughput rose to 888,900 barrels of oil per day (bpd) in the reported quarter, from 862,000 bpd a year earlier.

Larger rivals Valero Energy VLO.N, Marathon Petroleum MPC.N and Phillips 66 PSX.N also reported upbeat results citing higher margins.

PBF also said that construction activities of its California-based Martinez refinery are expected to be completed by February 16, 2026 following a fire last year. The company expects the refinery's catalytic cracking unit to start in the first week of March.

(Reporting by Katha Kalia in Bengaluru; Editing by Tasim Zahid)

((Katha.Kalia@thomsonreuters.com;))