Two relatives of reputed mob chieftain Carlo Gambino were charged today with conspiring with four others -- to smuggle 90 pounds of heroin into New York City. The two men were ordered held in lieu of $3 million bond each.

Assistant U.S. Attorney Mark A. Summers said the 90 pounds of heroin, intercepted in a shipper's office in Milan, had a wholesale value of $10 million.

Brothers Rosario Gambino, 37, and Guissepe Gambino, 33, the manager and owner, respectively, of Valentino's Supper Club in Cherry Hill, N.J., were arrested Tuesday night at the restaurant officials said. There precise relationship to Carlo Gambino was not disclosed.

One alleged co-conspirator, Paul Rizzuto, 42, was arraigned in U.S. District Court in Brooklyn today and held on $25,000 bail.

In addition, three brothers were being held by police in Milan for their alleged role in the operation. The government is attempting to have them extradited to face trial in Brooklyn.

Summers said the heroin, found by police Tuesday, was to have been loaded aboard an Alitalia jetliner bound for Kennedy International Airport. l

The record high ball was set for the Gambinos in U.S. District Court here after the judge received a request from a judge in Brooklyn who held the sealed indictment against Rizzuto.