Spokesman Joe Evangelisti said the bank set the original Jan 21 release date to allow greater time to account for its purchase of Washington Mutual Inc assets, as well as the Martin Luther King holiday on Jan 19 and inauguration of Barack Obama as U.S. president the next day. He said, though, that the bank would be ready to report results sooner.

It was not immediately clear whether the acceleration suggests that results will be better or weaker than investors expected. Evangelisti declined to comment on that matter.

Analysts on average expected a profit of 5 cents per share, according to Reuters Estimates.

The fourth quarter is the first full three-month period since New York-based JPMorgan on Sept 25 spent $1.9 billion to buy most assets of Seattle's Washington Mutual, the largest U.S. banking failure.

On Dec 11, JPMorgan Chief Executive Jamie Dimon said on CNBC television that November and the first part of December were "terrible" periods for JPMorgan. Analysts have since lowered their earnings forecasts for the industry, including for Bank of America Corp and Citigroup Inc .

JPMorgan shares rose 40 cents to $25.31 in after-hours trading following the bank's afternoon announcement. They fell $1.06, or 4.1 percent, to $24.91 in the regular trading session.

(Reporting by Jonathan Stempel; Editing by Bernard Orr)