El Segundo-based Active Interest Media Inc. is selling the operator of one of the largest boat shows in the world to a British publishing and events firm.

Informa PLC of London announced Tuesday it is acquiring Yachting Promotions Inc. for $133 million, including $5 million that is subject to the business meeting performance and operating targets, from the publishing and events company.

Yachting Promotions operates five boating shows, including the Fort Lauderdale International Boat Show, which is marketed as the largest in the world. The show draws 100,000 attendees, 820 exhibitors, and more than 1,200 boats each November.

Active Interest Media purchased Yachting Promotions, which is headquartered in Fort Lauderdale, in March 2006 during a period when the company was rapidly acquiring specialty magazines and associated trade shows.

Active Interest Media publishes magazines, puts on trade events, and produces videos for niche audiences. The company is divided into six groups – Equine Network, Home Group, Healthy Living Group, Marine Group, Outdoor Group, and Creative Home Group.

Informa is the owner of the Monaco Yacht Show, which is the leading yachting and boating event in Europe. With the addition of Yachting Promotions Inc. to Informa’s portfolio, the United States is expected to represent more than 50 percent of the Group’s revenues, according to the press release.

“Following three years of private discussions, we are delighted to bring YPI into the Group,” Stephen A. Carter, Informa Group chief executive, said in a press release. “It will deepen our leadership in the growing international yachting and boating sector, with its attractive exhibitions complementing our existing ownership of the Monaco Yacht Show.”

The deal is expected to be completed this month.