FILE PHOTO: Warren Buffett, CEO of Berkshire Hathaway Inc, plays bridge as part of the company annual meeting weekend in Omaha, Nebraska U.S. May 6, 2018. REUTERS/Rick Wilking/File Photo

(Reuters) - A unit of Berkshire Hathaway Inc denied a report on Sunday that it reached an agreement to allow extraction of lithium from its geothermal wells in California, a project that could offer U.S. carmakers and battery producers a secure supply of the metal.

“There is no agreement in place with anybody to allow extraction of lithium or any other minerals from the geothermal wells in California,” Jessi Strawn, a spokeswoman for Berkshire Hathaway Energy Co, which is majority-owned by Warren Buffett’s conglomerate, said in an emailed response to a Reuters query.

The Financial Times earlier had reported, citing people familiar with the discussions, that the venture has been in talks to supply Tesla Inc with lithium, a component for batteries to power electric cars.

Berkshire Hathaway’s geothermal wells could produce up to 90,000 tonnes of lithium a year worth $1.5 billion at current prices, the report said, citing a fundraising document.

Tesla did not immediately respond to a request for comment outside normal business hours.