U.S. safety regulators are investigating a potential for brake failure in General Motors Co vehicles that could affect up to 6 million trucks and SUVs sold from the model years 1999 through 2003.

The National Highway Traffic Safety Administration opened a preliminary probe on March 30 of the GM vehicles after receiving 110 consumer complaints that corroded brake lines on Chevrolet and GMC pickup trucks and SUVs made it difficult for them to stop the vehicles.

The problem allegedly caused three crashes but no injuries have been reported, NHTSA said in a document posted on its website.

The investigation comes at a time when the auto industry's handling of safety issues is under intense scrutiny following massive recalls by Toyota Motor Corp.

A preliminary evaluation has been opened to determine the frequency, scope and safety consequences of the alleged defect in the subject vehicles, NHTSA said.

GM spokesman Alan Adler said the company is aware of the issue and is working with NHTSA to look at possible causes and consequences of the alleged defect.

It remains unclear how many of the estimated 6 million vehicles sold for those model years might be affected by the potential problem, Adler said.

In 37 of the 110 complaints filed with the agency, inspection by GM dealers found a brake line failure.

(Reporting by Soyoung Kim, editing by Gerald E. McCormick)

General motors