HONG KONG (Reuters) - India's Tata Motors Ltd TAMO.BO has signed a deal to receive a $3 billion one-year bridge loan from Citigroup C.N and JPMorgan JPM.N to help finance a potential purchase of luxury brands Jaguar and Land Rover, sources familiar with the deal said on Tuesday.

A combo of pictures shows the logos of carmakers Tata Motors of India (L), Jaguar (top R) and Land Rover (bottom R) during the first media day of the 78th Geneva Car Show March 4, 2008. Tata Motors Ltd has signed a deal to receive a $3 billion bridge loan from Citigroup and JPMorgan to help finance a potential purchase of luxury brands Jaguar and Land Rover, a source familiar with the deal said on Tuesday. REUTERS/Denis Balibouse/Arnd Wiegmann

“It is signed, but it’s still at an early process,” said one of the sources, who was not authorized to speak to the media.

A separate source briefed on the deal later said the loan would be for one year.

Citigroup, JPMorgan and Tata Motors all declined to comment.

Tata is expected to agree on a deal by the end of the month to purchase the two well-known UK brands from U.S. auto maker Ford Motor F.N, according to media reports in India.

The Indian firm could raise up to $4 billion on domestic and overseas debt markets, based on its previous announcements and media reports.

Tata is believed also to need money to help pay for the manufacturing of the world’s cheapest car, the Nano, that it will launch in the second half of the year.

But Tata will face a tough debt market environment, as a global financial crisis has raised the premiums demanded by investors, especially from riskier Asian issuers.

Standard & Poor’s placed Tata Motors on review for a possible downgrade in January from its current high-yield “BB+” rating, citing the potential increase in its debt load from the acquisition of the venerable Jaguar and Land Rover brands.

Investors have also worried about the amount of leveraged loans held by U.S. lenders, which had in previous years helped to finance a boom in mergers and acquisitions by lending the money to acquirers and then selling off the loans to other investors.

Investors are eagerly awaiting quarterly earnings results from U.S. financial firms, including Lehman Brothers LEH.N and Goldman Sachs GS.N later on Tuesday, for further clues about soured debt holdings in the sector.

JPMorgan on Sunday announced it would buy stricken Bear Stearns BSC.N for only $2 a share, valuing the U.S. investment bank at about $236 million in a bailout that had received partial backing from the Federal Reserve.