LONDON — Imax Corp. has signed its first deal with Cineworld, the U.K.’s leading exhibitor by market share, to install digital Imax screens in three theaters.

Imax already has a strong U.K. presence with 12 digital screens in the Odeon chain, plus four traditional Imax theaters.

The three Cineworld screens will be installed under a revenue-sharing deal in existing multiplexes in Edinburgh, Sheffield and Nottingham.

The Edinburgh location will open in December, with Nottingham and Sheffield scheduled to open in early 2012.

This deal is a significant coup for Imax, which has been working hard to convince U.K. exhibitors apart from Odeon about the merits of retrofitting standard multiplexes with its large-format digital screens.

Cineworld has been experimenting this year with its own large-format system, the Sky Superscreen, in London’s O2 arena.

Despite some skepticism about the Imax technology and revenue-sharing deal, Cineworld toppers have been impressed by the box office grosses at Odeon’s dozen Imax sites.

“If Imax works for other people, we should look into it,” said one Cineworld exec earlier this year. “We know exactly how well it’s doing for Odeon. We like to be trendsetters, but if other people have jumped into the cold water and it works for them, we’re prepared to follow.”

Cineworld has around 26% of the U.K. box office, followed by Odeon with 23% and Vue with 22%. Vue has resisted Imax, instead developing its own successful large-screen format, VueXtreme.