WASHINGTON, D.C.— A federal grand jury yesterday indicted Joseph Y. Longmire, a former executive of the Dallas-based explosives manufacturer ICI Explosives USA Inc., for participating in a criminal conspiracy to fix prices and rig bids on commercial explosives sold in Kentucky, Illinois and Indiana, said the Justice Department.

Thus far, 13 explosives manufacturers and distributors, and three executives--including ICI and one other ICI senior executive--have pleaded guilty to antitrust conspiracies in the Department's ongoing antitrust investigation of the explosives industry.

Joel I. Klein, Assistant Attorney General in charge of the Department's Antitrust Division said, "We are continuing our aggressive efforts to bring to justice those who have undermined competition in this billion dollar industry. The investigation has already resulted in numerous guilty pleas and in the assessment of criminal fines of nearly $40 million."

With approximately $1 billion in sales in the United States, commercial explosives are primarily used in the mining, construction, and oil and gas industries.

The one-count indictment, filed in U.S. District Court in Owensboro, Kentucky, charges Longmire with conspiring with other competitors between the fall of 1988 and sometime in 1993 to fix prices, allocate customers, and rig bids on certain explosives offered for sale in portions of western Kentucky, southern Illinois, and southern Indiana.

The indictment charges that as part of that conspiracy Longmire and other competitors discussed and agreed to increase a surcharge to certain purchasers of drilling, loading and blasting services from 3 percent to 4.5 percent.

Longmire was president of ICI's Southeast Subsidiary Group, and subsequently a vice president of ICI, from July 1988 until March 1993.

The indictment results from an ongoing investigation of the commercial explosives industry being conducted by the Division's Litigation I Section with the assistance of the Federal Bureau of Investigation.