Warren Buffett sold an additional $982 million of Bank of America Corp. stock as his conglomerate continues to shrink its investment in the second-largest US bank.

His Berkshire Hathaway Inc. has trimmed the stake by a total of almost 13% in a series of sales since mid-July, generating $5.4 billion in proceeds. Berkshire disclosed the latest disposals in a regulatory filing late Tuesday, detailing sales on Aug 23, 26 and 27.

Buffett has held silent about his reasoning while whittling the highly profitable bet — an investment that began when the stock was trading near $5 in 2011. The shares were up 31% this year before the selling spree. They have since slid 10% to $39.67.

The string of sales signals Buffett’s biggest pullback from an investment that long served as a stamp of approval on the leadership of Bank of America Chief Executive Officer Brian Moynihan, whom the 93-year-old investor has repeatedly praised in public.

Berkshire still remains the bank’s biggest stockholder — with 903.8 million shares worth $35.9 billion, based on Tuesday’s closing price.

This article was provided by Bloomberg News.