WASHINGTON (AP) _ After a five-month delay, the Senate has approved the nomination of Mary L. Schapiro to head the Commodities Futures Trading Commission.

The Senate's action late Tuesday came just hours after Sen. Jesse Helms, R- N.C., ended his objections to Schapiro's appointment.

Helms used his discretion as a senator to delay the approval of Schapiro, who was nominated by President Clinton in April, as well as several other nominees to smaller agencies.

Helms sought to pressure outgoing Agriculture Secretary Mike Espy to reinstate a senior worker for the Agricultural Research Service in Athens, Ga., who was reassigned after criticizing the agency's benefits policy toward homosexual workers and their companions.

The dispute, which had nothing to do with Schapiro, was resolved when Espy agreed to reinstate the worker, pending a hearing.

Schapiro, a member of the Securities and Exchange Commission, sought to put the best face on the lengthy delay.

''While it was not wonderful to have so much uncertainty, I loved where I was staying so it was not a painful process for me,'' she said. Her appointment was noncontroversial and was even welcomed by the heads of powerful Chicago futures and commodities exchanges.

The CFTC, which supervises nearly 55,000 professionals in the nation's commodities and futures markets, has been without a permanent leader since former Chairwoman Wendy Gramm stepped down in January 1993.