Ambassador Theater Group, the largest owner-operator of theaters in the U.K., will expand its stake in Broadway real estate, launching a multimillion-dollar renovation of the Hudson Theater, a midtown Manhattan venue that isn’t currently classified as Broadway.

The addition of a new venue amounts to a major development on Broadway, which in boom times is limited by the small number of theaters — seating more than 500 each and mostly located in midtown Manhattan — that are deemed Broadway. The number of Broadway theaters currently stands at 40; the Hudson, which currently can seat as many as 700, will bring the total number of Broadway theaters up to 41 when the venue reopens during the 2016-17 season.

ATG, which has long harbored hefty international ambitions and in 2013 purchased Broadway’s Lyric Theater, will partner with Millennium & Copthorne Hotels on the project. Previously a Broadway house — its last listed Broadway offering was 1968 play “Mike Downstairs” — the Hudson is currently part of the Millennium Broadway Hotel.

Millennium & Copthorne and ATG haven’t set an exact price tag for the renovation, but among the changes on the to-do list are front-of-house improvements, new seating, a lounge, and enhanced restroom facilities, as well as backstage and tech upgrades that will bring the venue up to Broadway snuff. Earlier this year ATG acquired ACE Theatrical Group, which has had a hand in the design, construction and operation of theaters including the recently renovated Kings Theater in Brooklyn and the Mahalia Jackson Theater in New Orleans.

Owning a theater is the surest money on Broadway — even flops pay rent — and as the ultimate arbiters of what ends up on the boards, landlords are among the most powerful figures in the theater industry. The addition of one more Broadway venue will help alleviate, however slightly, the theater logjam that’s become a fact of life in the industry these days, as hit musicals continue to occupy real estate longer than ever before and as more and more producers, including Hollywood studios, aim to get into the potentially lucrative Broadway game.

In addition to theater ownership, ATG also has a hand in producing internationally, and although the umbrella organization hasn’t had much luck as a lead producer on Broadway, one of its subsidiaries, Sonia Friedman Prods., is a major player on both sides of the Atlantic, particularly when it comes to plays. Such non-musical fare seems likely to be the best fit for a theater the size of the Hudson. (Next year Friedman will produce “Harry Potter and the Cursed Child” on the West End).

ATG owns a total of 46 theater venues in the U.K., the U.S. and Australia, and also owns a number of British ticketing services including ATG Tickets and Group Line.