Cineworld has warned it may need to raise more money in the event of further coronavirus restrictions or film delays due to Covid-19.
It swung to a $1.6bn (£1.3bn) loss for the six months to June as its cinemas were closed under lockdown.
“There can be no certainty as to the future impact of Covid-19 on the group,” it said.
The cinema giant said it had reopened 561 out of 778 sites worldwide as lockdown restrictions have eased.
Six of its theatres in the UK remain closed after cinemas were forced to shut temporarily for several months from mid-March in an attempt to contain the spread of Covid-19.
The lockdown closures meant group revenues sank to $712.4m in the first six months of the year, compared with $2.15bn a year earlier.
The group loss this year also marks a huge fall from the pre-tax profits of $139.7m seen in the first six months of 2019.
Cineworld said it was still in talks with lenders to negotiate waivers on banking agreements, which fall due in December and in June next year.
The company warned that it might have to take action if current measures aimed at preventing the spread of coronavirus were tightened.
“If governments were to strengthen restrictions on social gathering, which may therefore oblige us to close our estate again or further push back movie releases, it would have a negative impact on our financial performance and likely require the need to raise additional liquidity.”
But it said recent trading had been “encouraging considering the circumstances”, with solid demand for Christopher Nolan’s spy film Tenet released earlier in September.