Financial channel Bloomberg TV has been sanctioned by Ofcom for breaching impartiality rules during the election campaign earlier this year.

On April 28 - one week before polling day - the station broadcast live coverage of the launch of Labour's business manifesto from its own London auditorium, followed by lengthy interviews with the Prime Minister, Gordon Brown and Patricia Hewitt.

Three viewers complained that Bloomberg had not given equivalent coverage to any other political parties during the campaign.

Bloomberg argued that it had offered each major party the use of its auditorium to hold a launch event but only the Labour Party had accepted.

Although Ofcom accepted that Bloomberg was not "deliberately biased" with its coverage, it felt that the breach of section 3.3 of the programme code, which requires broadcasters to maintain due impartiality on "major matters" of political controversy, was "sufficiently serious to merit the imposition of a statutory sanction".

Ofcom's Content Sanctions Committee has directed Bloomberg to broadcast a statement of Ofcom's finding at 11am on three consecutive days.