General Motors Corp. (GMGMQ) has begun mailing early retirement offers to its hourly workforce with the goal of clearing out thousands more employees, according to a person familiar with the situation.

The bankrupt auto maker is offering factory workers a $25,000 vehicle voucher and up to $45,000 to retire from GM under a deal reached last month with the United Auto Workers. Workers can get the voucher and up to $115,000 to quit early and cut ties with the company.

Employees have until July 24 to decide whether to take the offer and another week to change their minds, the person said. Around 7,600 workers took a similar offer extended earlier this year.

It will be GM's fourth buyout offer since 2006. The auto maker's hourly ranks have shrunk by roughly 45% since then.

All of GM's 54,000 UAW-represented workers will receive an offer, which GM is in the process of mailing to workers. GM has declined to disclose a specific target for reductions.

But the auto maker is saddled with excess workers amid plans to halt much of its production this summer and to idle or close 14 factories and three parts and service centers by the end of 2011.

Typically GM would disclose details of retirement offers through meetings at its factories, but since so many plants are closed, many workers will learn of the program via packages sent through the mail.

-By Sharon Terlep, Dow Jones Newswires; 248-204-5532; sharon.terlep@dowjones.com

248.204.5532 (w)

248.217.7648 (m)

*****************************************