The bank's management recently briefed unions on the planned expense reductions, reassuring them that there wouldn't be any new job cuts after the bank laid off 1,750 staffers last year, the source said.

"The management told us there wouldn't be any layoff plan," the source said, "but that there were expenses to be cut between 150 and 200 million euros, by 2015."

The plan is the latest sign that big European banks are having to resort to further cost cuts to try to boost profits as investment banking revenues remain erratic and retail and consumer lending are depressed by weak economic growth.

On Friday, a union source told Reuters that Credit Agricole's larger rival BNP Paribas (BNPP.PA) planned to spend 1 billion euros over three years to pare down its business.

The Credit Agricole cost cuts would be found by not replacing departing employees, as well as unspecified cuts in the areas of real estate and information technology, the source said the unions were told.

A Credit Agricole spokeswoman declined to comment on the plan, which was first reported by newsletter Agefi.

Like other banks, Credit Agricole has been selling assets and streamlining its business to meet stricter regulations after the 2008 financial crisis. It was forced to take a 1.96 billion euro in writedowns on the sale of its Greek unit, Emporiki Bank, in November.

($1 = 0.7524 euros)

(Reporting by Lionel Laurent and Leila Abboud; Editing by Hans-Juergen Peters)

• A Permanent Economic Emergency