Tata motors owns UK <a href="http://www.jaguar.com/gb/en/new_xj/" target="_blank">luxury car-maker</a> Jaguar Land Rover, the running of which will revert to CEO Ralf Speth.
No immediate replacement has been announced, meaning the group will remain without a leader in overall control of its operations in different countries.
Forster will continue to serve as a non-executive director.
In a statement released by Tata Mr Forster stated, “my personal circumstances make it difficult for me to continue to perform the challenging duties of managing the thriving global activities of the Tata Motors Group with its main activities in India and the UK and increasingly in additional overseas markets.”
Forster joined Tata motors in February 2010 from General Motors where he headed its European division.