The curtains at Melbourne's iconic Astor Theatre may be drawn for the final time next May when the current operator's lease expires.

Relations between the owner of the St Kilda building and the tenants have left any future business relations untenable.

George Florence has been showing films on the Astor's one big screen since 1982.

The heritage-listed building was saved two years ago when businessman Ralph Toranto bought it from St Michael's Grammar School, which wanted to use it instead for performing arts.

The Astor's Tara Judah said Mr Toranto was seen then as a "white knight".

"He said he was buying it as a passion, not as a commercial venture," she said.

However Ms Judah said the lease they were offered would have been unaffordable.

"There has never been a time that we've been allowed to sit down and say, these are our hopes for the future of the Astor, this is what we need to make that happen, this is how we can work together," she said.

"I have absolutely no idea what the landlord intends.

"I think he has a responsibility to the public of Melbourne to say something, but so far we have not been told what those plans will be."

Dale Smith, a spokesman for Mr Toranto, said various ongoing disputes saw the businessman withdraw his offer.

"It's been an unhappy marriage," he said.

Mr Toranto is hoping to find new tenants next year who would continue to operate a cinema, Mr Smith said.

"This is a recent decision we will have to make, say, in the new year," he said.

Mr Smith questioned the argument that the lease would have been financially crippling.

"What was more crippling: paying the insurance or all these legal matters?"

The Astor, one of the last of Melbourne's grand Art Deco film palaces, has been in operation since 1936.