Nineteen gasoline station dealers in the Houston area filed suit against Exxon Co. USA, saying Exxon has conspired to keep retail gasoline prices artificially high.

Exxon and gasoline wholesalers have broken antitrust laws and deceptive trade rules by using discriminatory pricing, the dealers said in the suit filed Friday.The dealers are asking for more than $5 million in damages from Exxon, five Exxon marketing representatives and Royce Groff Oil Co., a San Antonio wholesaler.

The attorney representing the dealers said franchise owners have had to charge higher prices to cover the artifically high costs of purchasing Exxon gasoline.