A new law in New York state now requires private employers with 50 or more workers to notify employees and the Department of Labor at least 90 days prior to a plant closing or mass layoff.

The legislation, known as the State Worker Adjustment and Retraining Notification (WARN) Act, has been signed into law by Gov. David Paterson. Proponents say the need for a stringent law at the state level comes after a number of companies have closed their doors in recent years and gave their workers little or no prior notification.

The measure will toughen the federal WARN law, which applies to companies that employ 100 or more workers and requires only 60 days notice to these workers. Businesses that fail to file a WARN notice in the allotted time period will be subject to penalties of up to $500 per day for each violation. The new law also gives the state Labor Commissioner the authority to order relief, including back wages and unpaid medical benefits, for employees who don't receive the required notice.

"For too long, workers in New York, given no notice in the face of immediate layoffs, have been unintentional victims of a federal law with limited enforcement provisions," said Labor Commissioner Patricia Smith.

The federal law, officials said, also lacks an administrative enforcement mechanism, which requires workers facing job loss to sue their employers privately. The new state law will close this loophole, which has allowed employers who fail to provide workers with a timely WARN notice to escape liability for such violations.