Victoria is one of the capital's busiest commuter stations

First in line for the upgrades will be major London terminals such as Victoria, Euston and Waterloo.

The company said it was in talks with private firms to raise funds to develop sites for more commercial use and will have more details by the end of 2005.

Network Rail said regional stations such as Leicester, Reading and Guilford were also in line for upgrades.

A spokesman for the company said there may also be scope for residential development.

The pace of the talks have picked up Network Rail spokesman

Victoria Station, England's busiest passenger terminal, could have a tower at the back of it, if engineers are able to build over the tracks.

A �500m revamp of its Tube station has already been announced by London Underground.

The mainline station itself would also be refurbished, but the building cannot be altered as it is protected by heritage status.

The spokesman said Euston had a similar problem as any new tall building on the site would block protected views of St Paul's Cathedral.

"At the moment we are in early discussions with interested commercial, private companies but the pace of the talks have picked up," the spokesman added.

"We are very confident these proposals will come through."