(Reuters) – Warren Buffett’s Berkshire Hathaway Inc on Saturday said fourth-quarter profit swelled, boosted by improved operating results and investment gains, and that it bought back an additional $6.9 billion of stock in the quarter.

Quarterly operating income rose 45% to $7.29 billion, or approximately $4,931 per Class A share, from $5.02 billion a year earlier.

Net income rose 11% to $39.65 billion from $35.84 billion, with both totals reflecting large gains from stocks such as Apple Inc. Apple alone represents nearly half of all the stocks Berkshire owns.

(Reporting by Jonathan Stempel in New York; Editing by Catherine Evans)