MANAGUA, Nicaragua (AP) _ President Violeta Barrios de Chamorro has asked the National Assembly to pardon five men accused of assassinating her husband, the opposition Sandinista party newspaper Barricada said Friday.

The victim, Pedro Joaquin Chamorro, was a prominent and highly respected newspaper publisher whose death in January 1978 helped ignite the revolution that overthrew the right-wing dictatorship of Anastasio Somoza in 1979.

Sandinistas, now Mrs. Chamorro's political foes, have praised her husband as a ''martyr for public freedoms.''

Barricada said the president sent a letter to the speaker of the national legislature asking the pardon, but officials contacted by The Associated Press neither confirmed nor denied the report.

Mrs. Chamorro said in June she would seek such a pardon.

Barricada said a government source gave it a copy of her letter and quoted it as saying, ''As the offended party, I have demonstrated to the National Assembly my feelings to forgive and forget toward those who were the material authors of the assassination and other related crimes.

''Therefore, I ask the pardon within the spirit of reconciliation which motivates me.''

No one answered repeated telephone calls to the presidency.

After Chamorro's assassination, the Somoza-era police arrested men described as hired gunmen: Silvio Pena, Domingo Acevedo, Silvio Vega, Harold Cedeno and Juan Ramon Acevedo. All remain in prison, but were never formally convicted.

According to Barricada, Mrs. Chamorro asked that they be pardoned along with 82 other common criminals.

After the Sandinistas took power in 1979, the Chamorro family brought a court case accusing Anastasio Somoza Portocarrero, a son of the dictator, along with Somoza official Fausto Zelaya and Cuban exile Pedro Ramos of being authors of the plot to kill Chamorro.

The newspaper said Mrs. Chamorro's petition did not say whether those men should be included in the pardon. All fled into exile after Somoza fell.

Her husband, publisher of La Prensa and long a vocal critic of the Somoza dictatorship, was ambushed and shot on a Managua street.

For decades, La Prensa was Nicaragua's only opposition newspaper. His death touched off violent demonstrations and rallied the Nicaraguan opposition to back the Sandinista revolution.

The leftist Sandinistas governed the country until April 25, when Mrs. Chamorro took office after winning February elections in a landslide.