Hollywood studio giant Warner Bros will make all of its 2021 film releases available on the HBO Max streaming service and in theatres at the same time, in the most significant industry reaction to the Covid-19 pandemic.
Most US cinemas remain closed and there has been relatively weak domestic ticket sales for the blockbuster Tenet.
Films such as the latest Matrix instalment and Godzilla vs Kong will simultaneously be released online and in cinemas. After a month they will only be shown in theatres.
"No one wants films back on the big screen more than we do," said Ann Sarnoff, chief executive of WarnerMedia Studios.
"We know new content is the lifeblood of theatrical exhibition but we have to balance this with the reality that most theatres in the US will likely operate at reduced capacity throughout 2021."
Warner had already decided to release Wonder Woman 1984 on HBO Max in December, as well as in cinemas.
Theatres have traditionally had exclusive rights to films for up to three months in an arrangement they have defended vigorously.
Shares of AMC Entertainment, the world's largest theatre operator, fell 4 per cent to $4.14 in afternoon trading.