Mario Benjamin Murphy, a Mexican citizen convicted in the 1991 murder-for-hire killing of a Navy cook in Virginia Beach, was executed tonight despite pleas for clemency from the Mexican government.

The U.S. Supreme Court and Gov. George Allen (R) rejected requests to avert the execution. Allen, in denying clemency, issued a seven-page statement concluding that Murphy had a fair trial, that there was no evidence of "discrimination based on national origin or ethnicity" and that the punishment fit the crime, which he called "a coldly premeditated, brutal murder."

Murphy, 25, died by injection at the Greensville Correctional Center here.

Before the injection was begun, Murphy said, "Today's a good day to die." After it started, he looked around, started to laugh and said: "I forgive all of you. I hope God does, too." He was pronounced dead at 9:09 p.m. Mexican officials and Murphy's attorneys said that under an international treaty, Murphy should have been allowed to consult with Mexican Embassy officials in Washington immediately after his arrest.

The Mexican government offered to imprison Murphy in Mexico if Allen would spare his life. Instead, he became the 43rd person executed in Virgina since the death penalty was reinstated in 1976.

Murphy was hired in 1991 by Robin Radcliff and her boyfriend to kill her husband, James Radcliff, so she could collect on a $100,000 life insurance policy, police said. Prosecutors said Murphy and two other men were paid $5,000 to kill Radcliff, who was then bashed in the head with a steel pipe. Murphy was never paid, according to John Adams, one of his attorneys.

Although Robin Radcliff, her boyfriend and the three men hired for the killing were convicted of conspiracy, Murphy was the only one sentenced to die and also was the only non-U.S. citizen. The others are serving life sentences.

Virginia Beach Commonwealth's Attorney Robert Humphreys has said that authorities did not tell Murphy about his rights under the 1963 Treaty of Vienna because he spoke fluent English and they did not know he was a Mexican citizen. Murphy was born in Tijuana, spent some time there and in San Diego until he was 11 and then moved to Virginia Beach.

Angel Gurria, Mexico's secretary of foreign affairs, said in a letter to Allen: "We have been unable to discover a satisfactory reason why our citizen should have been singled out among his codefendants for the especially harsh penalty of death."

Allen administration officials said prosecutors asked for the death penalty for Murphy because he alone of the five both participated in the killing and recruited accomplices.

As the execution time drew near, members of Murphy's family held a candlelight vigil outside the prison gate. Sylvia Murphy, his mother, said: "He said he was very sorry for what he did. He did not mean to do it. We are not educated people. We were not aware of his rights."

Murphy's was one of 61 foreign death row inmates in the nation who were not informed of their rights under the international treaty, said Robert F. Brooks, another of Murphy's attorneys. More than 30 are Mexican, he said.

Adams said, "We're concerned that if we continue in this country to fail to abide by our international treaty obligations, then other countries won't abide by our request when our citizens are arrested."

Jerry A. Rankin, president of the Southern Baptist International Mission Board, which represents more than 4,200 missionaries in 130 countries, had urged Allen to commute Murphy's sentence, citing the same reasons given by Adams. "I am horrified to think of the potential repercussions in Mexico and other countries and its potential harm to our missionaries," he said in a Sept. 11 letter.

The U.S. State Department said Tuesday that it would send its "deepest regrets" to the Mexican government for the state's "apparent failure to provide Mr. Murphy with consular notification." It stopped short of trying to prevent the execution.

Three months ago, Texas executed a Mexican man for a 1985 murder, despite Mexican government objections that he had not been informed of his Vienna Convention rights. Angry demonstrations took place in Mexico. CAPTION: Mexico offered to imprison Mario Murphy if his life was spared.