Robert J. Kelleher, who helped lead tennis into the modern open era while serving as president of the U.S. Lawn Tennis Association and who later became a U.S. District Court judge, died June 20 at his home in Los Angeles. He was 99.

Former Los Angeles mayor Richard Riordan, a friend, confirmed the death but did not disclose the cause.

Mr. Kelleher was captain of the U.S. Davis Cup team in 1962 and 1963. Before 1968, only players classified as amateurs were allowed to enter the major international tennis tournaments. Professionals were not welcome at Wimbledon and what are now called the Australian, French and U.S. opens.

But appearances belied the reality.

“I had been around for a great long time and knew how tennis was operating, how the so-called amateurs were all paid under the table,” Mr. Kelleher told the Los Angeles Times in 2000, the year he was inducted into the International Tennis Hall of Fame.

Senior District Judge Robert J Kelleher was the oldest-serving federal jurist in the nation and a onetime tennis pro. He died Wednesday in Los Angeles. (Associated Press)

When tennis great Billie Jean King introduced him at the hall’s ceremony, she said that “every professional tennis player living” should thank Mr. Kelleher, the Harvard Law Bulletin reported in 2000.

“He gave the big push we needed to make open tennis a reality in 1968,” King said. “Instead of peanuts we were getting under the table as amateurs, it was prize money on top of the table, and the game took off.”

From his perspective, “it was a political coup,” Mr. Kelleher said in 2000 in the Times.

“The entrenched people who had been running tennis — nationally and internationally — liked it the way it was,” he said. They had “the political strength to defeat it several times before. It was a real uphill pull to succeed.”

But succeed in challenging tennis’ establishment is what Mr. Kelleher and his British counterparts did in the spring of 1968. Herman David, then chairman of the All-England Club, which hosts Wimbledon, and Derek Hardwick, then chairman of the British Lawn Tennis Association, joined with Mr. Kelleher to pressure the International Lawn Tennis Federation to allow amateurs and professionals to compete together and be paid legitimate prize money.

Mr. Kelleher aimed to legitimize international tennis — and make the sport more popular and profitable.

“Tennis is a marvelous sport to play and watch, but we’ve swallowed some of our own myths about its popularity,” Mr. Kelleher said in February 1968 in Sports Illustrated. “Look at the sports pages, look at TV. Where is tennis? It is a minor sport that has a chance to realize its potential as a healthful recreational and consequential spectator sport if it can get up-to-date.”

Once the tournaments were flung open to all players, the sport did flourish. Fans streamed through turnstiles to see such stars as King, Jimmy Connors and Chris Evert; television executives paid increasingly higher fees for the rights to broadcast matches; and the athletes collected fatter paychecks. Tennis also experienced a recreational boom.

In 1967, Mr. Kelleher had been elected president of the U.S. Lawn Tennis Association (now called the U.S. Tennis Association). After his two-year term ended, he returned to practicing law and was appointed to the federal bench by President Richard M. Nixon in 1970.

Among his most famous cases were the 1977 espionage trials of Christopher Boyce and Andrew Daulton Lee, who were convicted of selling classified information to the Soviet Union. The men’s stories were turned into the book and movie “The Falcon and the Snowman.”

The judge attained senior, or semi-retired, status in 1983 and never officially retired from the bench.

Robert Joseph Kelleher was born March 5, 1913, in New York. As a child, he served as a ballboy at the West Side Tennis Club in Forest Hills, which hosted the U.S. national championships from 1923 to 1978. (Under its new name, the U.S. Open, it moved to its current home at Flushing Meadows in Queens.)

Mr. Kelleher received a bachelor’s degree in 1935 from Williams College in Massachusetts, where he was captain of the tennis team, and a law degree in 1938 from Harvard University.

In 1940, he married Gracyn Wheeler, one of the top American female tennis players of the late 1930s. As a mixed doubles team, they won a range of tournaments, including the 1947 Canadian national championship. His wife died in 1980.

Their two children, Robert Jeffrey Kelleher and Karen Kathleen Kelleher, became lawyers. Besides his children, Mr. Kelleher is survived by Sigrid Draper, his longtime companion, and three grandchildren.

After college, Mr. Kelleher became a trial lawyer in New York and an associate attorney for the Department of the Army before serving in the U.S. Naval Reserve.

When World War II ended, he moved to Los Angeles with his wife, a Californian who didn’t like New York, and set up a private law practice.

In 1962, Mr. Kelleher was chosen to be the non-playing captain of the U.S. Davis Cup team. His squad beat Australia in the 1963 Davis Cup, the first time the Americans had won the men’s international team competition since 1958. As the team traveled the globe, Mr. Kelleher realized that they were ambassadors of tennis and their homeland.

“I believe in tennis as a game to benefit the community and the country,” he told the Times in 1962. “I believe it’s good for America to have a good Davis Cup team. I feel a team of athletes, well behaved and well trained, is better than a dozen Peace Corps.”

— Los Angeles Times