New Delhi, Nov. 3 -- The sole representative of Agratas Energy Storage Solutions Pvt. Ltd's Chinese-owned technology partner, AESC Apollo, has stepped down from the board of the Tata Group's battery venture less than two years after joining it and just ahead of the firm's move towards commercialization, regulatory filings show.

The departure of Gordon Louis Chin comes amid a decline in outstanding payments for its services and equipment to AESC and Agratas building its own manufacturing capabilities. The move marks a shift in the partnership's board-level representation just as the Tata firm prepares to scale up manufacturing in India and the UK.

According to company filings with the corporate affairs ministry, which were reviewed by Mi...