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Nov 13 (Reuters) - Spain's biggest refinery operator Repsol SA REP.MC is considering a reverse merger of its upstream unit with potential partners, including U.S. energy producer APA APA.O, Bloomberg News reported on Thursday, citing people with knowledge of the matter.

APA shares were up 7.1% at $25.59.

Repsol in 2022 entered into a deal to sell a 25% stake in the upstream division to private equity firm EIG Global Energy Partners, valuing the whole business around that time at $19 billion including debt.

The upstream unit has net hydrocarbon production of about 571,000 barrels of oil equivalent per day, according to the company website.

The report comes weeks after Repsol CEO Josu Jon Imaz said the upstream unit was being prepared for a liquidity event in 2026, which could mean an IPO or a reverse merger with a company listed in the U.S.

The Spanish company has held exploratory discussions with potential merger partners for the business, including APA, the Bloomberg report said.

An APA spokesperson declined Reuters request for comment, while Repsol did not immediately respond.

(Reporting by Tanay Dhumal in Bengaluru; Editing by Shilpi Majumdar and Shailesh Kuber)

((Tanay.Dhumal@thomsonreuters.com; Twitter: https://twitter.com/TanayDhumal;))