General Motors announced it has extended cash rebates and interest-free loans on most of its vehicles until July 31, Reuters reported.

The news agency noted that GM has been offering rebates of up to $4,000 and interest-free loans for up to five years for much of the summer. Under the new program, GM reduced rebates on a few models but launched deals on 2004 vehicles with rebates of up to $1,500, the report added.

Vehicle sales have slowed from stronger levels at the end of 2002 amid the weak labor market and general economic uncertainty, Reuters said, adding that another factor is "incentive burnout," a term that refers to the fact that Big Three incentives are now taken for granted by many consumers and fail to draw them into showrooms.

Reuters said that, last month, GM's average per-vehicle incentive hit $3,934, a 51 percent increase over June 2002 and the highest average among large car makers. Despite the generous discounts, GM's inventories were about 21 percent above normal at the end of June, the report added.