Odeon & UCI Cinema Group has been sold to US-based company AMC Entertainment in a deal worth £921m (€1.09bn $1.21bn).
The cinema chain, which has 242 theatres and 2,236 screens, is currently owned by private equity firm Terra Firma, which paid £475m for Odeon and £295.8m for UCI in 2004 before merging the two groups together the same year.
Terra Firma had twice tried to sell the chain in 2011 and 2013, although both attempts proved unsuccessful.
AMC, which was acquired in 2012 by Chinese conglomerate Dalian Wanda – the world's largest movie theatre operator, led by China's richest man Wang Jianlin – confirmed Odeon will operate as its subsidiary and remain based in London.
"This is a once-in-a-generation opportunity to acquire Europe's leading cinema chain and create the world's biggest and best theatre operator," said Adam Aron, AMC's chief executive and president.
Aron admitted last month's Brexit vote had created some uncertainties, but added the company was "encouraged that current currency rates are highly favourable to AMC with the pound falling to a three-decade low versus the dollar".
The sale, which remains subject to regulatory approval from the European Commission, will bring AMC's theatre tally to 627 with more than 7,600 screens in eight countries.