Tata's acquisition of Jaguar and Land Rover is part of the firm's strategy to break into developed markets around the globe, sources said last night.

The Indian industrial giant will be named as the preferred bidder for Jaguar and Land Rover tomorrow. Tata has had its £1 billion bid accepted by Ford - which is selling the two luxury carmakers together - the employers of 13,320 people across the Midlands.

While Tata refused to comment on the sale yesterday, the firm did say it was keen to expand into other markets around the world.

A spokesman said: "When one market is at its peak, another is in a trough. It is important to be in different markets to reduce risk."

The firm has beaten off competition from rival Indian firm Mahindra and Mahindra and private equity group One Equity Partners.

Final negotiations are expected to be completed in the next six weeks before the sale is completed. Sources at Land Rover said yesterday: "It is definitely Tata. There is one final meeting and so long as there are no last minute hitches, which are not expected, then an announcement will be made on Friday."

Officials are coming to the UK from India for the announcement, and the deal will be worth around £1 billion.

Staff and the Government are all supportive of the deal, the source added, while it will ensure the companies and the jobs stay in the West Midlands. The news was welcomed by union leaders last night. Des Quinn, industry officer for the Transport and General Workers' Union section

of Unite, said: "We cautiously welcome this development, although the devil will be in the detail.

"We thought the Tata bid was in the best interests of our members. They come from a manufacturing background, and the experience of other people they have taken over has been good.

"They allow the management to manage and are investing in it. They are cash rich and they can afford the price, as well as invest in the future.

"Generally we think they are the better buyer for Jaguar and Land Rover."

Earlier this year Tata bought Corus for £4.3 billion, while the firm also owns Tetley Tea in the UK.

Mr Quinn added that the Mahindra bid fell down because of its links to private equity.

"When a private equity firm buys a company, the cost of buying it often goes onto the companies books.

"If anything then goes wrong how do you refinance the business?"

Tata also seemed more committed to both brands, rather than Mahindra which is thought to be predominantly interested in Land Rover because of its own 4x4 roots.

There were doubts about how long a private equity buyer would keep the two companies, before selling them on again, added Mr Quinn.

"One Equity said they had some long term investments, but in private equity that is not the normal route."

Ford bought Jaguar in 1989 for £1.6 billion and paid £1.7 billion for Land Rover in 2000.

However, its Premier Automotive Group, which includes the two brands, lost £166 million last year.

A spokesman for Ford said: "No final decision has been made. We are still in negotiations with the interested parties.

"We expect an outcome early next year at the latest and can add nothing more at this time."