They climbed over 3% a day after the Indian firm revealed plans to split its car and truck businesses into separate units.
Tata says that will allow it to compete better with Indian market leader Maruti Suzuki.
It also anticipates a possible stock listing in the country by South Korean rival Hyundai.
Now the cars unit will house Tata's lucrative Jaguar Land Rover operation.
The company was the best performing stock among Indian automakers last year, as it turned profitable on the back of strong luxury vehicle sales.
It's risen another third this year, far outperforming the overall rise in local auto stocks.
Analysts say the demerger should allow both the car and truck businesses to operate with greater freedom.
Tata says shareholders will have an identical holding in both firms after the split.
The company says the proposal will now be presented to the board.
It says it will take a year or more after that to get the necessary approvals.
