Adds details on the refinery in paragraph 2, Monroe Energy response in paragraph 3

By Nicole Jao and Shariq Khan

NEW YORK, March 18 (Reuters) - At least two key processing units at Monroe Energy's 190,000-barrel-per-day refinery in Trainer, Pennsylvania, went offline on Wednesday before they were restarted, people familiar with plant operations said.

The refinery has restarted the 68,000-bpd fluid catalytic cracker after the outage, one of the sources said. The 12,000-bpd alkylation unit, is in the process of coming back online.

A Monroe Energy spokesperson declined to discuss operations at the refinery.

U.S. jet fuel prices have surged since the start of the U.S.-Israeli war on Iran as the attacks disrupt crude and feedstock exports from the Middle East. Any operational disruptions could exacerbate an already tight fuel market, sending prices even higher.

The Trainer refinery, located southwest of Philadelphia, is owned by Monroe Energy, a subsidiary of Delta Air Lines. The plant produces jet fuel and other transportation fuels including gasoline and diesel.

(Reporting by Nicole Jao and Shariq Khan in New York; editing by Deepa Babington)

((Email: Nicole.Jao@thomsonreuters.com; Twitter/X: @ByNicoleJao; Phone: +1 646 540 2216))