Frontiere had been hospitalized for several months with breast cancer, the team said in a statement announcing her death which was posted on its Web site.

She took charge of the Rams after husband Carroll Rosenbloom died in 1979 and moved them from Anaheim, California, to St. Louis in 1995.

During her time in charge, the Rams made the playoffs 14 times, won 13 postseason games and reached the league's title game three times. The Rams won their first Super Bowl championship in 1999 and reached the title game again after the 2001 season, losing to the New England Patriots. The Rams also played in the 1980 Super Bowl while still in Los Angeles.

"It's been my privilege for 28 years to work for a loyal, generous, and supportive owner who was totally committed to her football team," Rams President John Shaw said in a statement. "This is an enormous loss for me and for the Rams' organization."

Frontiere was born in St. Louis in 1927 as Violet Francis Irwin and her name was changed to Georgia three years later. Her mother had a musical act, in which Frontiere and her brother performed.

Frontiere married a U.S. Marine at 15, though the marriage was annulled during the Second World War. Her second husband died in an automobile accident, and she later married an actor, a stage manager and a Miami television personality. Then, according to her accounts to various media outlets, she attended a party at Joseph Kennedy's house where she met Rosenbloom, and the couple was together for 22 years.

Rosenbloom drowned in 1979 while swimming off Golden Beach, Florida, and she inherited the team at age 52. She fired Rosenbloom's son Steve, who owned 6 percent of the team, two weeks into the next exhibition season.

Her next husband, Dominic Frontiere, served nine months in federal prison after he scalped thousands of tickets to the team's appearance in the 1980 Super Bowl and didn't pay taxes on the income.

In 1995, Frontiere moved the team to her native St. Louis, where she was guaranteed a new, $260 million stadium and almost $20 million in annual profit.

The Rams reached the Super Bowl in Atlanta after the 1999 season, with coach Dick Vermeil asking players to "take Georgia to Georgia," and defeated the Tennessee Titans.

In St. Louis, Frontiere created the St. Louis Rams Foundation with Vice Chairman Stan Kroenke and gave away more than $5 million to local charities. She also sat on the board of the local United Way chapter, the Saint Louis Symphony Orchestra and other civic and charitable groups.