Wells Fargo & Co on Wednesday said it is freezing its cash-balance pension plan for all employees, and has issued layoff notices to 548 workers in uptown Charlotte, North Carolina, the former home of Wachovia Corp.

The moves will reduce costs, spokeswoman Mary Eshet said. Wells Fargo bought Wachovia for $12.5 billion at the end of 2008, and has said it expects about $5 billion of annual cost savings related to the merger, with job cuts beginning this quarter. It has not said how many jobs it plans to cut.

Wells Fargo said it will maintain its 401(k) retirement plan, under which the San Francisco-based bank matches employee contributions for up to 6 percent of total pay. Many other large companies have also cut back traditional pension plans.

A significant number of the 548 layoffs are in investment banking, a smaller unit of the former Wachovia that Wells Fargo has been reducing in size. These job cuts began in February, and will continue through late July, the bank said.

The government is expected on Thursday to say Wells Fargo needs billions of dollars of capital to cope with a potentially deep economic downturn. Results of government stress tests on 19 large U.S. banks are due for release that afternoon.

(Reporting by Jonathan Stempel; Editing Bernard Orr)