A former executive for a military equipment company pleaded guilty to conspiracy Thursday in Washington federal court, three years after he began cooperating with prosecutors in what has become the largest prosecution of alleged foreign corruption payments.

Richard Bistrong, formerly of Armor Holdings Inc., pleaded guilty to one count of conspiracy to violate the Foreign Corrupt Practices Act and other statutes. He faces up to five years in prison, and as part of his plea, he agreed not to request a downward departure from the federal sentencing guidelines, said Laura Perkins, a trial attorney in the U.S. Justice Department’s fraud section.