Berkshire Hathaway, run by billionaire Warren Buffett, extended its selling of Bank of America shares, and has shed more than $3.8 billion of the second-largest U.S. bank's stock since mid-July.

Berkshire sold approximately 19.2 million Bank of America shares for about $779 million between July 30 and Aug. 1, according to a Thursday night regulatory filing.

Buffett's conglomerate has sold 90.4 million Bank of America shares since July 17.

It remains the Charlotte, North Carolina-based bank's largest shareholder, owning 942.4 million shares, or about 12.1% of reported shares outstanding, worth about $37.2 billion.

Berkshire must continue reporting sales until the stake falls below 10%. It will report second-quarter earnings on Saturday morning.

The sales began after Bank of America's stock price had risen by about two-thirds since late October, and traded at more than 1.2 times book value.

That boosted the value of Berkshire's shares to over $45 billion, more than triple the $14.6 billion it paid for them.

Berkshire has invested continuously in Bank of America since 2011, when it bought $5 billion of preferred stock.

That purchase signaled Buffett's confidence in Bank of America Chief Executive Brian Moynihan's ability to restore the bank to health following the 2008 financial crisis.

Buffett, 93, one of the world's most revered investors, told CNBC in April 2023 he liked Moynihan "enormously" and at the time did not want to sell the bank's stock.

Berkshire is based in Omaha, Nebraska. Its operations include Geico car insurance, the BNSF railroad and several dozen other insurance, energy, industrial and retail businesses. (Reporting by Jonathan Stempel in New York; Editing by Christopher Cushing)