Oxfordshire Rail operators First Great Western and Thames Trains have had their say on proposals to merge them.

The Strategic Rail Authority wants the two companies and Wessex Trains to merge so services in the south and west would be run by a single company.

In its response to the SRA proposals, Great Western, which runs inter-city services via Didcot, has said the merger would improve the infrastructure, provide shorter and more regular journeys, and help develop integrated transport.

Managing director Mike Carroll said: "There are a number of compelling reasons why the 'Greater Western' franchise is the best way forward for customers.

"Local and long-distance services from London Paddington operated by one instead of two companies will mean we can use the existing infrastructure more effectively and improve punctuality across the network. "It is vital we make the most of our rail infrastructure, and the combination of a single operator and more cohesive timetabling elsewhere will undoubtedly do that."

However, Thames Trains, which runs services via Oxford, has remained cautious about the proposals and would not give out any details of its report.

Spokesman John Radley said: "We can see some of the benefits of having one franchise that covers the majority of rail movements out of Paddington.

"But we are really not saying very much at the moment."

If the SRA's series of proposals are approved, the number of train operators could fall from 25 to 20 in five years and to 12 by 2010.

The authority's chairman, Richard Bowker, said that if he could not persuade companies to "do a deal", he would force through the reforms.