A grade A-listed building, which is the site of some of the finest medieval archaeology in the capital, is being brought back to effective use for the first time in more than 60 years.

Tron Kirk, at the heart of Edinburgh's Royal Mile, has lain largely unused since it ceased to be a functioning church in 1952.

Conservation organisation Edinburgh World Heritage (EWH) wants to turn it into a visitor centre telling the story of the city's heritage sites as well as those around Scotland.

The proposal has moved a step closer to reality after it received the green light by the City of Edinburgh Council. The local authority's finance and budget committee approved plans to grant EWH a lease on the church on the grounds that it will secure funding for the restoration within two years.

EWH chairman Willy Roe said: "As a category A-listed building at risk at the heart of the world heritage site, the Tron Kirk is a natural priority for us, and finding it a sustainable use is key to its future.

"The restoration of the building offers Edinburgh a unique opportunity to create an accessible and sustainable centre from which to tell the fascinating stories of the old and new towns, and provide learning about our globally recognised world heritage sites."

The Tron, built between 1636 and 1647, has been in council hands since 1972. It houses the excavated remains of the medieval Marlin's Wynd, revealed by digs in the mid-1970s.

It was let for use between 2000 and 2006 as an information centre and became a Fringe venue and bar during last year's festival season, which will be repeated this summer.

A study prepared for the council committee noted that during the past five years, approaches were made to the local authority to use the Tron for commercial purposes but "most did not address the prerequisite of allowing access to the public to view the archaeology".

If brought back to use by EWH, the building would "provide a focal point for visitors to the Edinburgh world heritage site and enable the finest medieval archaeology in Edinburgh to be viewed by visitors", the study said.

"EWH will conserve the fabric and fit out the Tron Kirk at no expense to the council, raising funds from various sources including grants. Long-term surplus income generated from visitors will be invested in the conservation and maintenance of historic buildings within the world heritage site."

The council committee backed the report's recommendation that it authorises talks with EWH on the granting of the long lease of the High Street building.

Mr Roe said: "I would like to thank council officers for their help and support, and look forward to working with them and other partners in the development of the project. This initiative will draw on the considerable expertise of Edinburgh World Heritage in conserving historic buildings, interpreting the city's heritage and fundraising for restoration projects.

"Needless to say, this will require a very large fundraising effort, but we are confident that people will see the value of the scheme.

"The Tron Kirk is one of Edinburgh's architectural treasures and our plan is to see it brought back to life for the good of the city."