Up to £125m of public money will be needed to bring London's 40 West End theatres up to standard.
West End theatres raise £1.5b each year for the economy
The theatres need £250m to fund a major refurbishment programme to bring them into line for the 21st Century.
Half of the money needed over the next 15 years would come from the theatres themselves but the rest may have to come from the public purse.
The Heritage Lottery Fund, the London Development Agency and local councils are being contacted to help.
The amount needed to upgrade the theatres was identified in a report written by The Theatres Trust, a national body which aims to protect theatres.
A spokesman from The Department of Culture said it was acting on behalf of the theatres to help raise half of the money.
"An issue that needs to be taken into consideration is that 37 out of the 40 theatres are listed buildings which makes it more costly to improve, but it's not impossible," he said.
"The government's view is that West End Theatres are very important for the city's economy raising £1.5b each year."
But he said it had to be recognised that the theatres were commercial ventures for which the government did not normally provide funding.
"All we can do is approach organisations on their behalf to help provide funding," he said.
A spokeswoman from Heritage Lottery Fund said: "Commercially owned theatres are a low priority for funding from Heritage Lottery Fund as are all privately-owned heritage attractions.
"It's public money and we have to spend it wisely."