LONDON/NEW DELHI (Reuters) - Virgin Group will try to win over shareholders with a sweetened bid for Northern Rock on the eve of a speech by the British Chancellor to Parliament about the struggling UK bank, an unsourced Sunday Times report said.

Chancellor Alistair Darling is set to tell the House of Commons today he will give bidders for Northern Rock — Virgin, investment group Olivant and an in-house proposal from its own management — two weeks to present their financing plans and their management teams, the Sunday Times said.

Darling will stand up in front of MPs to tell them about a financial plan to convert Northern Rock's debts into bonds, which will increase the hopes of a private-sector rescue for the bank.

A statement from the Treasury about Northern Rock is expected early today, a Treasury spokesman said.

"I believe we will save by far and away the most jobs," Virgin chairman Richard Branson told journalists in New Delhi, India, as he accompanies Prime Minister Gordon Brown on a trip to Asia.

"I believe that our offer capitalises the company in the largest way ... I believe we have the best management team," said Branson.

Responding to criticism from the Conservative party that Branson's relationship with Brown put Virgin in a favoured position Branson said he only had one short chat with the prime minister on the subject.

"When he was walking down to tell the press about Goldman Sachs' approach he mentioned it to me all in 30 seconds and that was it," said Branson.

The UK government plans to back the proposal by advisers Goldman Sachs to convert loans of around £25 billion ($49 billion) to Northern Rock from the Bank of England into bonds, which can be sold on to private investors.

Virgin is prepared to cut its proposed stake in the bank from 54 percent to 45 percent, the Sunday Times report said, without naming sources.

Virgin and its consortium intend to inject £650 million into the group and are looking to obtain a further £650 million from existing investors through a rights issue, to be underwritten by investment bank Morgan Stanley.