St Enoch station could be among those refurbished under proposals

Strathclyde Partnership for Transport (SPT) wants to "transform" the current system and create a second loop serving the east end of Glasgow.

Alistair Watson, SPT chair, said: "I believe it is imperative the subway is modernised and extended eastwards."

Funding would need to be secured for the vision, which SPT said could take between 10 and 15 years to realise.

Mr Watson said it would be a challenge to have the projects completed by 2014, when Glasgow hopes to host the Commonwealth Games.

'Bold visions'

SPT said the subway could be modernised at an estimated cost of �270m.

This would involve new trains and enhanced stations.

The second option would see a new circular route in the east end, interchanging with the subway at Bridge Street, St Enoch and Buchanan Street.

Proposed stations St Mungo's Onslow Duke Street Celtic Park Dalmarnock Newhall Dalmarnock

This would cost an estimated �2.3bn, which SPT described as a "huge cost" which would need to be looked at.

This option is to be investigated further alongside extending the system to Maryhill and the Scottish Exhibition and Conference Centre (SECC).

Mr Watson said: "If Glasgow aspires to become a major European city then we need ambition to create a world-class transport system to match that."

Ron Culley, SPT chief executive, added: "We need to face the facts that the current system is fraying at the edges.

"These proposals contain bold visions."

The organisation plans to approach the Scottish Executive, Glasgow City Council and possibly developers with a view to funding the projects.

Steven Purcell, leader of Glasgow City Council, said: "It's vital that SPT and the Scottish Executive get together to make sure funding can be found for these ambitious plans.