Paul L. Bloom, a lawyer in the Carter administration’s Energy Department who pursued oil companies for overcharging and won billions of dollars in refunds for customers, the government and others, died Oct. 10 in Chevy Chase, Md. He was 70.

The cause was pancreatic cancer, his family said.

James Schlesinger, as the first secretary of the new Department of Energy, appointed Mr. Bloom in 1977 to investigate oil companies’ compliance with oil pricing regulations. President Richard M. Nixon had begun oil price controls as a temporary measure at the time of the Arab oil embargo of 1973, but enforcement of the regulations was lax.

Mr. Bloom, as special counsel for compliance, ended up accusing 33 of the 35 largest oil producers and refiners of overcharges amounting to $11 billion. By 1987, the government had collected $6 billion in refunds as a result of Mr. Bloom’s suits.

But other than the pleasures of success, it was often a thankless job. Oil companies complained, with some justification, that the rules, and Mr. Bloom’s interpretations, were maddeningly arcane. Economists said price controls, by definition, weakened market efficiency. Consumer groups criticized Mr. Bloom as being too willing to settle cases, often on terms favorable to the industry.