The companies have been in negotiations for almost three months after emerged as the leading bidder ahead of rivals , a private equity concern, and automotive group Mahindra and Mahindra.
Tata Motors is known for its fleet of sturdy trucks and buses and functional passenger cars, including the $2,500 Nano, the world's cheapest car which it plans to launch later this year in India.
Tata has previously said it will keep most of the manufacturing in the UK, with 16,000 people employed in Britain by and . Unions have supported the Tata takeover.
is ending its 21-year investment in Land Rover as the US housing slump and job losses curb demand for the luxury marquees.
Jaguar sales dropped 33% in the US and Europe in the first two months of the year, while Land Rover sales fell 13% in the US and 7.7% in Europe during the period.