LONDON (AP) — A British judge ordered Shell to pay hundreds of thousands of dollars after the oil company pleaded guilty to failing to follow safety regulations at one of its plants.

Shell was fined more than $535,000 and ordered to pay $74,500 in costs on Wednesday for a 2003 accident in which dangerous gas escaped from a corroded pipe at the Stanlow petrochemical plant in Ellesmere Port, about 200 miles northwest of London.

The company pleaded guilty last month to failing to comply with accident hazard regulations. The judge, Roger Dutton, said the fine was lower than it would have been had Shell been found guilty after taking the case to trial.

Britain's Health and Safety Executive said the gas escape was caused by Shell's failure to properly inspect and maintain the pipe. Stanlow general manager Yuri Sebregts said changes have been made to ensure the problem does not recur.

The Stanlow complex, which manufactures a range of petrochemical products, is owned by the Shell Chemicals UK Ltd., a part of the Shell Group.