WASHINGTON, Oct. 13 — Representative Bob Ney, the first member of Congress to confess to crimes in dealings with the lobbyist Jack Abramoff, pleaded guilty to corruption charges Friday but said he would not immediately resign. Ney, Republican of Ohio, announced last month that he intended to plead guilty, admitting that in return for official acts, he had accepted tens of thousands of dollars' worth of gifts from Mr. Abramoff that included lavish trips, meals and tickets to concerts and sporting events. He faces a prison term of more than two years.