IBM Corp. confirmed Friday that it has closed a customer-service call center in Tucson.

"The customer support services provided by the Tucson call center will now be delivered by other existing call centers," IBM said.

The company would not say how many employees were affected by the closure or provide other details. IBM operates call centers for clients, as well as providing sophisticated computer systems for call-center management.

But IBM spokesman Jeffrey Tieszen said the call-center move does not affect the company's main Tucson operation, a major storage-systems development center at the University of Arizona Science and Technology Park.

IBM, which stopped sharing local employee counts several years ago, employs an estimated 1,350 people at the storage-systems center in Tucson.

The last time IBM divulged local employment figures was in 2009, when the company reported 1,432 full-time-equivalent employees as part of the Star 200 survey of the region's largest employers.

Under federal law, most employers with 100 or more employees must provide 60-day advance notification of plant closings and mass layoffs to the state's program for dislocated workers, if the layoffs affect at least 50 workers or about a third of the site's workforce.

Notices filed with the state Department of Economic Security under the Worker Adjustment and Retraining Notification (WARN) Act in the past year don't include any filings by IBM in Tucson.

In February, company officials confirmed that layoffs were taking place in some business units as part of a workforce "rebalancing," but they offered no details.

More recently, IBM confirmed that it has offered a one-time, voluntary "transition to retirement" program that allows eligible workers to receive reduced pay for working reduced hours and exemption from layoffs, if they agree to retire on or before Dec. 31.

In recent years, IBM has come under sharp criticism from former employees, pro-union groups and lawmakers for eliminating jobs in the U.S. while adding workers overseas.

According to Alliance@IBM, a nationwide IBM unionizing campaign that tracks layoffs at Big Blue, the company has an estimated 94,000 U.S. workers, down from the 105,000 IBM last reported in 2009.

Worldwide, IBM reported 433,362 employees at the end of 2011, including employees of wholly-owned subsidiaries. In 2009, the company reported 399,409 employees worldwide.

Contact Assistant Business Editor David Wichner at or 573-4181.