A top organizer for the Iron Workers union has been charged with using the union's credit card to ring up more than $50,000 in personal expenses, including travel and meal costs for his wedding and honeymoon.

Fred G. Summers was arrested by FBI agents on Thursday at Reagan National Airport as he returned home from a business trip. He appeared in U.S. District Court yesterday and pleaded not guilty to a 76-count indictment accusing him of embezzling from a labor union and making false entries in union records.

Summers was indicted after federal prosecutors reviewed the union's books. The investigation grew out of a two-year probe into allegations involving D.C. police corruption. The link to both cases is Jake West, the union's longtime president. Prosecutors have been trying to determine whether West, a friend of former police chief Larry D. Soulsby's, ever used union money to do favors for Soulsby.

Soulsby's attorney, Gerard F. Treanor Jr., has repeatedly declared that Soulsby denies any wrongdoing. West and his attorney did not return calls yesterday.

Summers, 50, of Alexandria, is executive director of organizing for the union, the International Association of Bridge, Structural, Ornamental and Reinforcing Iron Workers. He is the third person to face federal charges in the two investigations.

Former police lieutenant Jeffery S. Stowe, a onetime roommate of Soulsby's, pleaded guilty in January 1998 to extortion and other charges and agreed to assist prosecutors. Michael J. Brennan, a former union official, pleaded guilty in March to using the union's money to entertain family and friends. He also agreed to cooperate. Stowe and Brennan are awaiting sentencing.

A law enforcement source described Summers as an acquaintance of Soulsby's, but the indictment makes no reference to the former chief. The indictment alleges that Summers had been stealing from the union for nearly five years, treating family members and friends to meals, entertainment and other benefits on more than 150 occasions.

The indictment says expenses included trips to the Indianapolis 500, a Washington Redskins football game in Chicago, a golf vacation in Palm Springs, Calif., and a weekend trip to Las Vegas. The expenses also include $729 in travel costs for Summers's 1998 wedding and $787 for honeymoon meals in Miami.

U.S. Magistrate Judge Deborah A. Robinson permitted Summers to be released on personal recognizance. Assistant U.S. Attorneys Carol Fortine and Steven Pelak, who are handling both investigations, declined to comment yesterday.

Summers said nothing as he left the courthouse. But his wife, Lauren Summers, said the case was without merit. "Carol Fortine has nothing better to do than to drum up allegations that are not true," Lauren Summers said.