NTT DoCoMo has moved the international court for arbitration in London to ensure that the Tata Group finds a buyer for the Japanese telco's 26 per cent stake in their Indian joint venture, Tata Teleservices BSE 5.57 per cent. The move has set the stage for a potentially bitter separation for the six-year-old joint venture which was once emblematic of the promise of the country's telecom sector. NTT DoCoMo said in a statement yesterday, DoCoMo submitted its request for arbitration to ensure that its right be exercised after Tata Sons had failed to fulfill its obligation, despite DoCoMo's repeated negotiations with Tata Sons regarding the sale of its entire stake in Tata Teleservices. It had moved the arbitration court on January 3, after the 90 business days it gave to the Tatas to find a buyer lapsed on December 3. As per the agreement between the two in 2008-09, the Tata Group was to ensure that its partner in the loss-making joint venture gets the higher of either half the investment it made, which amounts to 7,250 crore rupees or the stake's fair market price in case the company fails to perform at a certain level.