BT and support services firm Capita are among four shortlisted companies bidding to run the BBC's £600m digital TV switchover targeted help scheme.

The two companies will also compete with support service companies EAGA and Vertex for the contract to deliver the scheme, the BBC and the department for culture, media and sport announced today.

Today's shortlist was finalised by the DCMS and the winning company will be decided by the BBC's executive board, led by director general Mark Thompson, which will oversee the chosen contractor.

The disclosure of the shortlist came today as the BBC Trust today formally confirmed approval of the Digital Switchover Help Scheme after concluding that it will not interfere with the financing of core BBC programme services.

It was first laid out in the government's white paper in March last year, as a way of subsidising the cost of switchover for the eldery and disabled.

"[The] BBC Trust has always made it clear that the BBC's participation in a help scheme would only be on condition that the BBC's programmes and services to licence fee payers must not be put at financial risk, and there would be a proper allocation of responsibilities between government and the BBC, with the government responsible for policy and the BBC for delivery of the scheme," the trust said.

"The trust is now satisfied that an agreement has been reached which meets these conditions."

The government announced in January this year that the scheme will be funded by £600m of money ringfenced from the BBC's licence fee income from now until switchover is completed, region by region, in 2012.

Financial help is being offered to those aged 75 and over, people with severe disabilities, and the registered blind and the partially sighted.

Other responisibilities for the scheme include providing equipment to convert television sets in the poorest households free of charge, with a modest fee of £40 for others who are just over that income bracket.

The government welcomed the trust's confirmation in an agreement that has been formally laid in the House of Commons today.

Tessa Jowell, the culture secretary, said: "The help scheme will help elderly and disabled people switch to digital.

"It will enable them to enjoy all the benefits, such as greater choice, that digital TV brings.

"The agreement we have signed with the BBC Trust means the BBC will now take responsibility for delivering the help scheme.

"We will continue to work closely with the BBC on the successful delivery to ensure the scheme works for the people who need it."

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