Chrysler says it will pay the remainder of a contract-ratification bonus to U.S. hourly employees earlier than agreed upon.

During intense negotiations last year with the United Auto Workers union, Chrysler agreed to pay workers a $3,500 signing bonus, half of it immediately and the other half paid if certain financial goals were met in four consecutive quarters.

But the auto maker is waiving that threshold because of the “the tremendous contribution you have all made to the performance of our facilities and the revival of Chrysler,” CEO Sergio Marchionne writes in a letter to employees.

The last half of the $3,500 bonus will be paid to workers Dec. 21. Under the original agreement, the bonus would not have been paid until first-quarter 2013.

The payoff is the latest good news for Chrysler’s unionized workers. Earlier this month, Marchionne announced 1,000 new jobs at the auto maker’s Warren, MI, truck plant to boost output of the well-received Ram 1500 pickup. Another 250 jobs could come to the auto maker’s Mack Avenue Engine complex in Detroit if market conditions allow.

Chrysler also is spending $40 million on a new flexible production line at its Trenton, MI, facility that will allow it to build both Tigershark I-4 engine, currently available in the Dodge Dart, and the Pentastar V-6.