By 9:15am GMT, they were 30 percent lower, taking their loss this year to more than 90 percent.
Cineworld's statement follows a grim evaluation by ratings agency S&P on Friday of rival AMC Entertainment, owner of the Odeon chain, which said the US-based group may run out of liquidity in six months unless it can raise more capital.
The entertainment industry has been among the heaviest hit by social distancing and other restrictions, with Walt Disney last week announcing plans to lay off roughly 28,000 employees, mostly at its US theme parks.
Cineworld began reopening in July after virus-related restrictions started to ease, but the further postponement of the James Bond film "No Time To Die" and others including Marvel's "Black Widow" have left the months ahead looking bleak.
"Without these new releases, Cineworld cannot provide customers in both the US and the UK... with the breadth of strong commercial films necessary for them to consider coming back to theatres," it said.
While some cinemas in China, the world's second-largest movie market, have reopened with strong audiences, there is a lack of major movies to watch on the big screen.
Studios have chosen to release some of this year's major planned blockbusters on Netflix or the Disney Plus streaming platform, and have canceled others until 2021.
The boss of rival chain Vue cinemas Tim Richards told BBC Radio: "Our problem right now is we have no movies, and this was a big blow for us."