BERLIN, Jan 23 (Reuters) - Germany's Economy Minister Robert Habeck on Tuesday said a much-anticipated roadmap for how a new generation of gas-fired power plants would be put out to tender was imminent.

The plan, with an estimated cost of 40 billion euros ($43.5 billion), aims to ensure enough electricity until renewable energy can overcome storage issues and inadequate grid technology to fully replace fossil fuels.

Habeck would not confirm that the strategy to build power stations that are initially gas-fired but ready for hydrogen to complement volatile renewables would be finalised by the end of Tuesday.

But he told a Q+A session at the annual Handelsblatt energy summit in Berlin, the government would "work out and present the proposals very quickly".

The country's top utility firms - RWE, Uniper and EnBW - have called for specific regulation to build the new gas stations that they say would not be economic without state help.

Habeck said there should be provisions to support capital expenditure and running costs until carbon emissions permits were expensive enough to favour clean energy production and disincentivse fossil fuels.

Government and industry sources told Reuters on Monday that German stakeholders were set to agree a deal on the power plant expansion strategy, which has drawn criticism from environmental campaigners keen to phase out coal and gas as soon as possible. ($1 = 0.9187 euros) (Reporting by Vera Eckert; editing by Christoph Steitz and Barbara Lewis)