Gladys Heidman, an instrumental figure in the formation of women's professional tennis, died Sunday at her home in Sante Fe, N.M. She was 81.

Ms. Heldman, the founder, publisher and editor of World Tennis magazine, began playing tennis at age 25. As an amateur, she was ranked No. 1 in Texas. She competed in the United States National Championships four times and at Wimbledon in 1954.

Off the court, Ms. Heidman was an indomitable force. She started World Tennis magazine in 1953 as a forum for the sport's views and problems. During its early years, the magazine was a one-woman operation, with Ms. Heldman as editor in chief, layout editor, art director and advertising director. She sold the magazine to CBS Publications in 1972.

The magazine helped transform Ms. Heidman into an advocate for women's tennis and one of the most influential people in the game.

In 1970, she used her status to help nine of the top women's players, led by Billie Jean King and Rosie Casals, form their own pro tour.

She arranged for the Houston Racquet Club to sponsor a tournament and had nearly all the players in the group sign $1.00 contracts with World Tennis to play in the tournament. Heldman persuaded her friend Joseph Culiman, chairman of Philip Morris, to donate prize money and sponsor five tournaments.

Despite suspensions and economic sanctions, the women's pro tour evolved into the Virginia Slims tour.

"Without Gladys, there wouldn't be women's professional tennis," King said in a statement Monday. "When I accepted that $1 contract from Gladysmore than 30 years ago, I knew we were all part of something special and that women's tennis had been changed forever because of her vision."

Gladys Medalie Heidman was born May 13, 1922, in New York City. Her father, George Z. Medalie, was a New York lawyer and judge. A Phi Beta Kappa graduate of Stanford University, she married Julius Heldman, a former United States junior tennis champion, in 1942.

The Heldmans' daughters, Carrie and Julie, were accomplished players; Julie was ranked as high as No. 5 in the world in 1969 and 1974.

Ms. Heidman was inducted into the International Tennis Hall of Fame in 1979. She is survived by her husband, her daughters and three grandchildren. [2003]