Four transport firms might bid for the right to run Bristol's rapid transit bus network, the Post has learned.

First Group and Wessex Connect, as well as Go Ahead and Stagecoach, have expressed interest in operating the city's new routes.

Details of how the contracts will be set up to run the high-speed bus services are yet to be decided.

But the Post has learned that the four big transport companies are all keeping their eyes on the project.

Most of them already operate their own high-speed guided bus systems in the UK. Go Ahead, for example, runs the Fastway service between West Sussex and Surrey to Gatwick Airport, while Stagecoach operates a supertram in Sheffield and a high-speed bus in Cambridge.

A Wessex Connect spokesman said it was keen to continue expanding its operation in the Bristol area and confirmed that the company, along with First, has already discussed the first rapid transit line with the city council.

Earlier this week North Somerset Council gave its official approval to Bristol's first rapid transit project, from Long Ashton to the city centre.

Following on from a link through Bath, the lines will be up and running by 2013 and will be the first in a network of high-speed transport systems around the Bristol area.

By 2026, Kingswood, Bath, Keynsham, Avonmouth, Patchway, Emersons Green and Bristol International Airport could all be linked through the rapid transit network.

It could see multi-million-pound contracts awarded for the running of the services, which are part of a major transport package aimed at easing congestion on the city's roads.

Martin Dean, spokesman for Go Ahead, said: "We would always look at any public transport projects around the country so we will certainly look at Bristol's rapid transit system. Our Fastway system is really, really successful and while we do not have any experience of running a rapid transit service in an urban context I think the concept is a really good one."

Steve Davies, depot manager at Patchway for Wessex Connect, said: "We don't know the full details yet but we are interested in expanding our business in Bristol and this could well feature in our plans."

Stagecoach said they had not yet decided whether or not they would bid for the contract but admitted that they were aware of the scheme.

Justin Davies, managing director of First Bristol, said: "We are aware of the plans for rapid transit in the city and we will be interested to see how these plans develop in the future."

Julia Dean, spokeswoman for the West of England Partnership, said: "Currently we have only spoken to the two local operators and at the moment we don't know what procedures we are going to follow.

"We do know that it's going to be an open and competitive process but we are taking legal advice on how it's going to be managed.

"The new Local Transport Act has changed the rules on bus partnerships and we need to maximise our opportunities so that we get the best value for the passenger and for local authorities. We need to make sure any service will be reliable and frequent."