By ALFONSO CHARDY

Herald Washington Bureau

WASHINGTON - The latest rash of airplane hijackings to Cuba has triggered an unusual exchange of diplomatic notes between the Reagan Administration and the government of President Fidel Castro.

Initially, the State Department. released a sharply worded press release accusing the Havana regime of failing to punish the hijackers. Later, however, after a Cuban response, the department issued a substantially softer statement that appeared to acknowledge that Cuba is trying to do something to curb incidents of air piracy,

On Wednesday - one day after the latest hijacking, the seizure of Eastern Airlines Flight 414, which was bound to New York from Miami - the State Department issued a statement that Cuba "must be held responsible, in part, for these acts for its failure to return hijackers to their country of origin or, at a minimum, to put them on trial and publicize the punishment of those found guilty."

The note went on to say that since June 1982, the U.S. Interests Section in Havana has urged the Castro regime on four separate occasions "to take effective measure to prevent future hijackings."

Cuba "has failed to do so," however, the note said.

That same Wednesday night, the Cuban government provided John Ferch, the head of the U.S. Interests Section in Cuba, with details on the punishment given to hijackers since 1980.

Cuban diplomatic sources in Washington said the information contained an explanation of Cuba's position on hijackings, especially those originating in the United States, and a list of the hijackings and the jail sentences or legal procedure applied in each case,

Responding to the Cuban note, the State Department released a "Hijacking Update" press release Thursday, acknowledging the latest Cuban information.

The latest American communication said the Cuban note "shows the punishment meted out by Cuba to hijackers has substantially increased in recent years."

The statement went on to list the status of nine accused hijackers imprisoned or held, in Cuba since 1982. State Department sources said the list published by the department was only a small portion of the Cuban response.

This is the list provided by the State Department:

* Sergio Ortega Rojas, Air Florida, Feb. 2, 1982; 12 years in jail.

* Fidel Rego Otano Delta, April 4, 1982; 20 years.

* Vicente Rego Otano, Delta, April 4, 1982; 20 years.

* Rogelio Rego Valenzuela, Delta, April 4, 1982; 20 years.

* Nivaldo Rojas Reyes, Marco Island, July 22, 1992; 15 years,

* Rosalino Rodriguez Cabrera, Marco Island, July 22, 1982; 15 years,

* Rigoberto Gonzalez Sanchez, Capitol Air, may 1, 1983; confined to psychiatric hospital and judgment pending.

* Cheerryl Ivonne Worthy, Capitol Air, May 12, 1983; detained at the disposition of the court.

* Carlos Arias Valdez, Eastern, May 19, 1983; detained at the disposition of the court.