Two Defense Department investigative units will probe for any wrongdoing in the billing by Rockwell International Corp. to the Ogden Air Logistics Center, officials say.

Hill AFB spokesman Len Barry said the Pentagon has assigned the Air Force's Office of Special Investigations and the Defense Criminal Investigative Service to look into the September 1987 negotiation for guided bomb parts between Rockwell and the logistics center.The center is based at Hill.

Barry said the probe is a result of a U.S. General Accounting Office report saying an overcharge of more than $1 million was made in the $38 million deal.

The defense contractor has complied with the Ogden ALC's request for an answer to the report, he added. However, Barry said that until the investigation is complete, the Air Force likely will not release Rockwell's response - or decide whether to follow the GAO's recommendation to seek reimbursement from the contractor.

Vince Vinci, a spokesman for Rockwell's Missile Systems Division in Duluth, Ga., said the contractor would make no public comment. However, Rockwell earlier denied intentionally concealing from the Air Force any lower subcontractor bids.

Overpricing can be unintentional, as a result of bid timing or mathematical error, said Paul Math, a senior associate director in the GAO's National Security and International Affairs Division.

The GAO reported that Rockwell said it disclosed lower bids that could save the government $409,017 on three bomb parts, but the company said the Air Force negotiator chose not to take the cheaper deal.

However, the GAO said government representatives, including the negotiator, said they had no knowledge of the lower prices.

The lower bids involve three bomb parts of seven the GAO said had been overpriced. For three other parts, the GAO said Rockwell acknowledged not disclosing lower prices but did not believe that resulted in the $248,987 in overcharges contended by the government.

The contractor said a seventh part was inadvertently overpriced by $4,434, the GAO reported.

The remaining $346,416 overcharge cited by the GAO was for Rockwell's overhead and profit.

The parts were for the GBU-15, a 13-foot-long winged bomb that can be guided to targets automatically or remotely by an aviator.

Jim Turner, a Pentagon spokesman, said the Defense Criminal Investigative Service looks for evidence of wrongdoing for possible criminal or civil prosecution.

"They look into any legitimate-sounding allegation," he said.

The Office of Special Investigations is the Air Force's internal detective squad. Neither group will comment publicly on investigations under way.

Rockwell a week ago entered conditional guilty pleas to conspiracy and contempt-of-court charges stemming from a $450,000 overcharge on an Air Force satellite contract.

The pleas will be stricken if the contractor successfully appeals a ruling in the case. The U.S. attorney in the Los Angeles court case said he will seek more than $1 million in fines against Rockwell.