The Indian carmaker is believed to have secured a £3bn (£1.5bn) one-year bridge loan from US banks Citigroup and JP Morgan.

According to Reuters, a deal has been signed but the financial agreement is still at an early stage.

Tata is understood to want to secure the acquisition of the two UK brands by the end of this month to avoid rising borrowing costs as a consequence of the worsening global credit crunch.

Concluding a deal quickly would also enable Tata to account for the purchase in this fiscal year.

Negotiations over the acquisition have been ongoing since Ford named Tata as its preferred bidder in January this year.

Analysts predict the combined sale could generate as much as $1.5bn (£750m) for Ford.