By LOUIS SALOME

A Hialeah man, wearing the clothes of a prison guard and riding in a jeep driven by a prison surveillance official, escaped last night from a Mexican penitentiary where he was being held on charges of attempted kidnapping and murder.

Gaspar Jimenez, 40, fled the prison in Mexico City with Carlos Estrada Ortiz of Colombia, who was being held on drug trafficking charges.

Jimenez, along with another Hialeah man, 28-year-old Orestes Ruiz Hernandez, was arrested July 23 and charged with the attempted kidnap of Daniel Ferrer, the Cuban consul in Merida, Mexico, and the murder of Ferrer's bodyguard. Ruiz is still in the Mexican prison.

Federal authorities here investigating Cuban terrorism believe that the Mexican murder-attempted kidnap plot was hatched in Miami.

Mexican officials said they have charged Pablo Gustavo Castillo. Castillo is also charged by Metro police with a bombing last April at the University of Miami student union building, and he is charged in federal court with lying on a passport application.

Law enforcement officials believe Castillo, Jimenez, Ruiz, Manuel Ortega and possibly other Miami men, were part of the came Cuban exile activist group based here and operating in the Caribbean and Latin America.

Ortega has pleaded guilty to the U-M bombing.

The FBI, which has been probing the Miami connections to the Mexican murder-attempted kidnap plot, said they had not verified Jimenez's escape, but added that they believed it was true.

An FBI spokesman here said it appeared from preliminary reports that Jimenez bought the cooperation of prison guards to make good his escape.

The American Embassy in Mexico City said morning press reports in that city indicated Jimenez and Ortiz either bought their way out of prison or had associates outside prison kidnap the children of a prison guard and the deputy chief of surveillance who drove the jeep in return for their helping the two men escape.

There have been reports from Mexico that Cuban Premier Fidel Castro had tried to persuade the Mexican government to release Jimenez and Ruiz to Cuban authorities.