Latino civil rights activists demonstrated in front of the Watergate South complex yesterday to protest the building's decision to fire a Salvadoran cleaning crew.

Corinna Chavez, 33, the Salvadoran American owner of Diana's Cleaning Service, said the Watergate informed her two weeks ago that her contract would be terminated at the end of July, abruptly ending seven years of service without any explanation.

The contract is being canceled a few months after one employee was told not to speak Spanish on the job and someone left threatening notes on Chavez's car, according to Chavez and the employee.

Chavez declined to speculate on the Watergate's motives for terminating the contract, citing the advice of a lawyer. But activists who joined her at the protest yesterday said they are investigating whether the crew was dismissed because the workers are Hispanic.

"For many years, they have only received praise. Now, they're discharged without an explanation," said Mario Acosta-Velez, executive director of the District-based Latino Civil Rights Center. "We don't know the details, but there is a suspicion of discrimination."

Chavez said three employees who make a little more than $9 an hour will have to find new jobs. She said she never received any complaints about their performance, and she produced a recent letter from former senator Robert J. Dole (R-Kan.), a longtime Watergate resident, saying the cleaning crew had "done a good job. They work hard and have always been eager to please--and very courteous."

"I'm very upset because these people have children, and they depend on this work," said Chavez, who supervised the crew. "What's going to happen to them?"

Three months before the contract was terminated, Chavez said, anonymous notes were placed on her car while she was working at the building. She showed one of the notes to reporters yesterday. In large typed print, it said: "You dirty spanish. You do not belong to this country. I want to let you know that a group of people are going to destroy you."

Chris Heuple, the building's resident manager, declined to comment. She also would not identify the building's board of directors.

"It seems that another scandal has emerged at the Watergate, and it appears that a travesty of justice has occurred," said the Rev. Brian Jordan, a Franciscan priest and an immigrant advocate, alluding to the infamous break-in at Democratic Party headquarters in 1972.

Jose Chavez, 27, who cleaned halls, offices and bathrooms at the complex, said that in March someone he did not recognize approached him while he was speaking with a co-worker in a hallway and ordered him not to speak Spanish.

"Now, I'll have to find another job," he said. "I have two children."

Jordan said a complaint had been filed with the Watergate management in April about the language incident and about a female employee being scolded for looking in a mirror. Corinna Chavez said she also reported receiving the harassing notes.

"The management has not done much about it," said William Stagg, of the Maryland-based Hispanic Resource Center. "Just because you do a humbling job, doesn't mean you should be treated without dignity."

CAPTION: Corinna Chavez takes part in a demonstration at Watergate South after her cleaning service contract was terminated. At left is the Rev. Brian Jordan. In front of Chavez is her 3-year-old daughter, Yesenia.

CAPTION: William Stagg, of the Hispanic Resource Center, holds a threatening note that Chavez said was left on the windshield of her car.