SALISBURY – In the coming days, the signs for all four regional Latitude Sports Club locations will be coming down and replaced with signs for the chain's new owner, Boston Sports Clubs.

John Grossi, who founded and ran the 22,000-member Latitude sports fitness chain, said Monday he sold his business to Boston Sports Clubs on Nov. 30. When asked how much he received for his four centers, Grossi would only say it was a multimillion-dollar deal. 

The switchover took place April 1, meaning the four fitness centers — located in Salisbury, Methuen, Peabody and Bradford — are now operated by Boston Sports Clubs, a Manhattan-based international company.

The parent company, known as Town Sports International Holdings, has 180 locations and calls itself the largest gym network in the Northeast. There are Boston Sports Club locations in Waltham, Cambridge, Boston, Newton, Lynnfield and Woburn. 

Grossi, who lives in the Point Shore area of Amesbury, said the transition will be seamless for Latitude members and most of his 450 employees. 

"It's a positive thing," Grossi said. "My biggest concern was my 450 employees, making sure they're going to a good place."

While Grossi said he decided to sell his clubs so he could devote more time to thoroughbred horse racing, he will remain involved as a consultant.

He said he has been in the gymnasium business for 35 years and opened the first Gold's Gym east of the Mississippi River in Everett. He opened his first Latitude Sports Club in 2005 and remained heavily involved until the deal in November. 

A call and an email to Town Sports International Holdings for comment were not immediately returned. 

Town Sports got its start in New York City in 1973 as a small chain of squash clubs, according to its website. By the end of the 1970s, it had shifted away from squash and joined the fitness craze. 

The first Boston fitness club joined the roster in 1996 and three years later, the company opened its first branch in Philadelphia. Today, there are clubs in eight states and two other countries. 

Staff writer Dave Rogers can be reached at drogers@newburyportnews.com. Follow him on Twitter @drogers41008.