THERE'S NO gentle way to announce the bad news of corporate retrenchment, but General Motors takes this year's prize for unnecessary roughness.

Seven days before Christmas, it told its 400,000 employees that it will close 21 plants -- it didn't say which -- in the next four years.

The company says it made the disclosure to head off escalating public speculation about its plans. Others say it was rushing to head off the possibility that its debt securities were about to be downgraded by Wall Street's credit-rating agencies, thus raising the company's borrowing costs. Either way, the company's decision left thousands of employees and their families to worry that they'd be on the hit list. Except top management. The leadership, says GM's chairman, Robert Stemple, "remains in place."