Suggestions that Detroit's 'Big Three' automakers might shift more production abroad if they cannot reduce labour costs were again aired today (14 June).

According to a Reuters report, an unnamed industry executive told the Wall Street Journal (WSJ) the three companies were resolved to move jobs overseas if they could not reduce their US labour costs.

The WSJ reported, citing auto executives, that the three automakers will seek unprecedented concessions from the United Auto Workers union in upcoming contract negotiations, Reuters said.

The report said the domestic group wants to close a gap in labour costs of $US10bn a year compared with their leaner Asian-owned rivals.

None of the three automakers or the UAW was available to comment to Reuters on the report.

The WSJ noted that the US automakers previously have agreed to costly labour contracts but now are united in believing they have no choice but to close the cost gap.

The WSJ added that the crucial round of contract talks with the UAW begins next month and a four-year deal on wages and benefits expires in September, according to Reuters.