WASHINGTON – A government agency that helps American businesses investing in developing countries has approved millions of dollars of loans to companies whose owners did business with Mafia figures and rebels in a bloody African conflict, records show.

The agency also awarded insurance to assist a company that is part of a Mexican energy conglomerate ordered by the Internal Revenue Service to pay more than $70 million in back taxes.

The Overseas Private Investment Corporation, which operates with about $5 billion in reserves, says it conducts background checks before awarding loans or insurance. But the agency acknowledged it missed some negative information about its clients the Associated Press found in a review of public records.

An OPIC spokesman said the agency checks some of the same public databases where the AP found the information.

For instance, the agency put on hold a $5 million loan to Globus International Resources “pending some further reviews” after the AP raised questions about evidence introduced in court showing Globus did business in the 1990s with Mafia figures who later were convicted of federal crimes.

Globus gave hundreds of thousands of dollars’ worth of shares to four Mafia stockbrokers and a mob-owned company between 1996 and 2000, according to court and SEC records.

Prosecutors alleged in 2000 that Globus was one of 19 companies that had their stock manipulated by the Mafia. The government never charged either Globus or its officials with crimes.

“Our due diligence didn’t turn up anything like that,” OPIC lawyer Eli Landy said. “This certainly raises a red flag.”

An OPIC spokesman defended the agency’s background checks. “We feel that the due diligence we do is very good and very thorough and we stand by that,” Lawrence Spinelli said.

The chairman of the Senate Foreign Relations Committee is not so sure.

After the AP provided details of its findings to his office, Senator Lugar, a Republican of Indiana, wrote the agency’s acting president, Ross Connelly, seeking more information on why OPIC agreed to provide assistance in these cases.

During its three decades of existence, OPIC has experienced its share of controversy.

In 2003, Congress ordered OPIC to be more open about its selection process and create a committee to bring together interested nongovernmental groups such as environmentalists and labor unions.

Doug Norlen, a member of that oversight panel, said OPIC still has significant improvement to make.

“They appear incapable of comprehending their own need for reform,” said Mr. Norlen, an environmentalist. He said OPIC has “shabby due diligence” on issues such as corruption, human rights, and environmental impact.

Congress created the agency in 1971 to give loans and insurance that were unavailable in the private sector to American companies doing business in developing countries.

In its 34 years, the agency has provided more than $160 billion to such projects. Recipients have included ExxonMobil, Unocal, and franchisees for Ruby Tuesday restaurants and Marriott hotels.

OPIC’s money comes from proceeds from its loans and insurance premiums rather than tax dollars.

OPIC agreed last fall to lend Globus $5 million to build a cold-storage warehouse in Moscow. OPIC did not know about Globus’s court-documented ties to organized crime.

Three men who pleaded guilty in the Mafia stock manipulation conspiracy – Anthony Stropoli, James Labate, and Salvatore Piazza – were among Globus’s initial private shareholders in 1996 and 1997, court and SEC records show.

Globus also gave consulting contracts to a company identified in court records as being controlled by the Mafia, and a business owned by Steven D’Apuzzo, a Mafia stockbroker who later pleaded guilty to racketeering and conspiracy to manipulate Globus stock.

D’Apuzzo told a judge he made more than $400,000 selling Globus shares and invested some of the profits in the brokerage he worked for, First Liberty Investment Group. That investment strengthened the mob’s hold on his investment firm, prosecutors said.