The biggest U.S. prosecution of individuals accused of foreign bribery was dropped after the government failed to win convictions of 10 people who went to trial among the 22 charged in the case.

The Justice Department Tuesday asked a federal judge in Washington to dismiss the indictment, which originally accused the security-industry officials of planning to make payments to a federal agent posing as a representative of the West African nation of Gabon to secure a stake in a fake $15 million deal for weapons and security gear.

It was the first time the government used a sting operation involving undercover techniques to charge violations of the Foreign Corrupt Practices Act.