JPMorgan Chase’s bonus pool for the corporate and investment bank may shrink as much as 2 percent this year as the firm completes performance reviews, three executives with direct knowledge of the process said.

But the amount won’t be set until the company closes out 2012, according to the sources.

The biggest US bank by assets, JPMorgan posted a record $19 billion in net income last year and may earn $20.8 billion in 2012.