General Motors Corp. will begin selling 15-passenger vans next month with standard stabilizing equipment, which the carmaker says will increase the safety of a vehicle that the federal government contends has a significant rollover risk, Associated Press (AP) reported.Meanwhile, AP added, Ford, which also makes 15-passenger vans, said it will begin affixing rollover-warning labels on new models of the van, similar to warnings on the company's sport utility vehicles.Ford reportedly said it also has strengthened the safety language in the vans' owners manuals, alerting drivers to the higher center of gravity and warning against abrupt maneuvers.AP noted that GM said in May it would install the stability enhancement systems as standard equipment in GMC Savana and Chevrolet Express vans beginning with 2004 models. The vans are made in Wentzville, Mo.The base price for a 2003 version of either GM van is $29,645, while the base price for the 2004 versions is $30,220, an increase the car maker said is typical for a new model, AP noted."Equipping our 15-passenger vans with ... stability enhancement systems makes what we believe is already a very safe vehicle even better," GM's executive director for structure and safety integration, Robert Lange, said.Associated Press noted that, last year, the government renewed a safety warning for 15-passenger vans, which often are used by churches, sports teams and other groups. About 500,000 of the vans are in use on U.S. highways.AP added that the National Highway Traffic Safety Administration (NHTSA) has said the vans have a dramatically higher risk of rollovers when fully loaded and should be operated only by experienced drivers. With 10 or more passengers, the vans have a rollover rate that's three times higher than when they have fewer passengers, according to NHTSA.A year ago, the National Transportation Safety Board called on Ford and GM to improve the safety performance of their 15-passenger vans, AP added.AP said GM began installing stability enhancement systems in passenger cars in 1997 and in sport utility vehicles in 2002 and noted that the NTSB has said GM's use of stability enhancement systems satisfies the agency's recommendation to evaluate and test measures to make the vans safer.But Public Citizen, a non-profit consumer advocacy group, has said the enhancements fall short and the vans should be redesigned, Associated Press said.