An official identified only as a high-ranking member of Nicaragua's ruling Sandinista movement has sought refuge with the United States, U.S. officials said last night.

The officials, who declined to give the individual's name or position, said the matter is being treated secretly until the person's security is assured.

{Last Friday, the Sandinista Defense Ministry released a communique saying that a former Army major -- described by local newspapers as an aide to Defense Minister Humberto Ortega -- left Nicaragua for the United States on Oct. 25, Washington Post correspondent Julia Preston reported from Managua.

{The man, identified as Roger Miranda Bengoechea left "in an abnormal fashion, taking advantage of the possibilities his host allowed him," the communique said. It said he had gone to the United States via Mexico.

{The Defense Ministry said Miranda Bengoechea "took this decision in the face of an administrative audit" within the ministry and accused him of having stolen "at least $15,000." It said an investigation was continuing and that Nicaragua would seek the extradition of Miranda Bengoechea.}

The U.S. officials provided no details but hinted that the incident took place recently in the Nicaraguan capital of Managua, where the person sought refuge in the U.S. Embassy. They gave no indication of whether the person requested political asylum.

Traditionally, when foreign officials seek U.S. asylum or refuge, the State Department orders silence until the person is in a location where U.S. authorities feel his or her safety can be ensured.

The apparent defection came just before the five-nation Central American peace agreement is to go into effect. It also came a day after Nicaraguan President Daniel Ortega left for the Soviet Union, in part to discuss the possibility of Soviet assistance with Nicaragua's deteriorating economy.