Two alleged top members of the Gambino organized crime family in New York were arrested yesterday on racketeering charges involving murder and loan sharking.

Aniello (Mr. O'Neill) Della Croce, the reputed No. 2 man in New York's most powerful organized crime group, and Anthony (TP) Plate, allegedly the Gambino's representative in Miami, were taken in custody the day after a federal grand jury in Fort Lauderdale handed down a sealed indictment charging them with a pattern of illegal activities going back 10 years.

The case is the third against major alleged organized crime figures in the past three weeks.

Joseph C. (Joe Bananas) Bonanno, allegedly the retired head of another New York family, who is now living in Arizona, was indicted in San Francisco late last month. He was charged with interfering in a Justice Department investigation of the laundering of alleged organized crime money through business run by his sons.

James T. Licavoli, allegedly the head organized crime chieftain in Cleveland, was indicted May 3 on federal racketeering charges involving the murder of an alleged rival mobster. He had been acquitted of state murder charges.

Sources said yesterday that the Della Croce and Licavoli cases were helped by the testimony of Aladena (Jimmy the Weasel) Fratianno, a confessed organized crime executioner who turned government witness. He has been descrined as one of the most valuable witnesses federal authorities have ever had on organized crime matters.

David Margolis, head of the Justice Department's organized crime section, said there was no special significance in the recent string of organized crime indictments. "We bring then when we get them," he said.

Edwin J. Sharp, head of the FBI's organized crime headquarters' unit, sid the recent cases against reputed top organized crime figures do illustrate a change in investigative strategy.

"We had a shift in our program about two years ago, and are concentrating on making cases against the high-level suspects, the guys who were thought to be invulnerable," he said.

The indictment against Della Croce and Plate charges that they are associated with "an enterprise which has been referred to as the 'Gambino mob'" Carlo Gambino, who died in 1976, was considered the "boss of bosses" in organized crime circles.

In a cover article on the "Mafia" two years ago, Time magazine described the struggle between Della Croce and Carmine Galente, another reputed New York mob family leader, for the top job.

According to the federal charges Della Croce ordered Plate to have a suspected FBI informer killed in 1974. Charles (Charlie Bear) Calise was found murdered, shot five times in the head in Rockland County, New York, in 1974.

The indictment also charged that Plate "extorted money from a variety of victims." In one instance, in Hallandale, Fla., in 169 Plate allegedly entered a man's office, jumped on his desk, put a knife in his chest, spit in his face and threatened to "bite chunks" from his face if he wasn't paid $40,000.

Sources said yesterday that the indictment was based mainly on the restimony of cooperating witnesses. Plate operates in Miami for the Gambino family in New York because the Florida city was declared an "open city" for organized crime by Al Capone more than 40 years ago. CAPTION: Picture, ANIELLO DELLA CROCE . . . reputed No. 2 man