UNDER pressure from Congress, the United States Federal Trade Commission said it will investigate allegations that market manipulation contributed to a 24-percent increase in gasoline prices in the past year.

The agency will study whether regulations are needed to prevent manipulation, the FTC said yesterday. The first step will be to seek public comments, the agency said.

"We understand that consumers are being hurt by high gas prices, and the commission remains vigilant in using its full authority to prevent unlawful behavior," FTC Chairman William E. Kovacic said.

The FTC's action came amid mounting pressure on the agency from Democratic law makers to use the authority granted in the energy legislation to craft regulations, Bloomberg News said.

"We are trying to look for manipulation that harms consumers" and determine "if people would be better off if we regulated" certain marketplace conduct, said David Wales, deputy director of the FTC's Bureau of Competition.

The comment period gives the public an opportunity to tell the FTC "whether we should have a rule and what it would look like," Wales said.