Life Time Fitness Inc. said Monday it has begun to explore spinning off its real estate holdings into a real estate investment trust (REIT) to unlock additional value for shareholders — news that sent the company's shares up more than 16 percent.

Such a move would essentially split Life Time in two, with one company operating fitness centers and the other invested in the underlying real estate assets.

The Chanhassen-based firm operates 112 health clubs across the country, each with an average size of 114,000 square feet.

"We think the net effect is a more efficient capital structure," said Jason Thunstrom, Life Time's vice president of corporate communications.

Analyst Sean Naughton,who covers Life Time Fitness for Minneapolis-based Piper Jaffray, told the Star Tribune that there can be benefits for shareholders with these types of activities. "The primary reason for doing this is to unlock some quote 'hidden value' inside of the company's real estate portfolio," Naughton said.

The company said it hired financial and legal advisers to explore the REIT conversion option and made the disclosure Monday to inform shareholders of the process. If approved by the board, a REIT conversion option would take nine to 12 months to complete.

The company said it also adopted a shareholder rights plan to preserve a financial maneuver necessary to conduct the conversion and to protect the company against a hostile takeover during the process. The shareholder rights plan expires on Aug. 21, 2015, or the first day after the closing of the proposed REIT conversion.

At several companies, activist shareholders have pressed management and directors to unlock shareholder value by selling their real estate. In May, Marcato Capital disclosed a 7 percent stake in Life Time and said it wanted the company to expand more quickly and consider options for its real estate. Some analysts and news accounts speculated Life Time executives would announce a REIT conversion plan at a June investor conference, but they didn't.

Naughton said the company has explored this option in the past, but the announcement to shareholders Monday and the filing of a shareholder rights plan is an indication to him that Life Time will proceed with the plan.

"It is more likely now than it has been in the past," Naughton said.

More recently, the company's stock came under pressure when its second-quarter results, announced late last month, missed expectations. Life Time shares hit a 52-week low of $38.01 on Aug. 7.

Life Time shares closed at $48.36, up $6.76, or 16.3 percent on the New York Stock Exchange Monday.

Thunstrom said the decision to explore a REIT came from Life Time's board. "It was very much driven by the board and not by a shareholder or group of shareholders," he said.

Patrick Kennedy • 612-673-7926