Police said they stopped a weaving car in Queens early this morning and discovered its driver, Queens Borough President Donald Manes, bleeding profusely from a severe wrist wound.

A knife with a four-inch blade was found in the front seat next to Manes, authorities said.

Manes, who has been borough president since 1971 and was recently reelected to a fourth term, underwent nearly three hours of microsurgery at Booth Memorial Hospital in Flushing to repair nerve damage.

He was reported in stable condition.

Police spokesman Officer Joseph McConville said highway officers stopped Manes' blue Ford LTD at 1:50 a.m. in the Elmhurst section of Queens near Shea Stadium.

Police said Manes was bleeding heavily from a deep cut in his left wrist and was "speaking incoherently" when he was found.

McConville said Manes also had several bruises on his left side and a cut on his left ankle that required six stitches.

"Obviously, he was not in control of his faculties," New York City Police Commissioner Benjamin Ward told United Press International. Ward added that police found no evidence of alcohol or drug use.

Police said they had not determined how Manes was wounded. Queens District Attorney John J. Santucci is investigating, and Manes is expected to be questioned in a few days, police said.

New York Mayor Edward I. Koch, who rushed to the Queens hospital at 3 a.m., told UPI this morning that Manes had appeared "sluggish" recently and speculated that the politician may have been affected by a liquid diet he had begun.

"He's a very sharp guy with a great sense of humor, and that seemed to be missing," Koch said.

Koch also suggested that Manes, who is said to lead one of the New York's strongest political machines, may have been upset by an intense battle in recent weeks over who should be named majority leader of the City Council. Manes' candidate, City Councilman Peter Vallone, won the election Wednesday.

Manes, a close associate of New York Gov. Mario M. Cuomo and former Democratic vice-presidential candidate Geraldine A. Ferraro, has indicated he is interested in running for mayor or perhaps for statewide office.