The three big Detroit automakers will seek unprecedented concessions from the United Auto Workers union (UAW) in contract negotiations, The Wall Street Journal reported in its online edition on Thursday, citing auto executives.

General Motors Corp., Ford Motor Co. and DaimlerChrysler AG's Chrysler Group are looking to close a gap in labor costs of $10 billion a year compared with their leaner Asian rivals, according to the report.

None of the three automakers or the UAW was immediately available for comment.

One industry executive told the Journal the three companies are resolved to move jobs overseas if they cannot reduce their U.S. labor costs.

In the past they have agreed to costly labor contracts, but this time the carmakers are united in believing they have no choice but to close the cost gap, according to the report.

The crucial round of contract talks with the UAW begins next month. A four-year deal on wages and benefits expires in September.