Chennai: Tamil Nadu Chief Minister J.Jayalalithaa on Sunday thanked Prime Minister Narendre Modi for the union cabinet's approval for extending the metro rail service here. In a letter to Modi, Jayalalithaa said: "I understand that the Union Cabinet has accorded approval to the proposal to extend Corridor I of Phase I of the Chennai Metro Rail Project from Washermanpet to Tiruvotriyur / Wimco Nagar covering a further 9.51 km at a cost of Rs 3,770 crore." She said more than 95 per cent of the physical work and financial expenditure on the Chennai Metro Rail Project so far, has been completed since work began in May 2011. "On behalf of the government of Tamil Nadu and the people of Chennai, I thank you for having accorded clearance for the implementation of the Chennai Metro Project Phase I Extension," she said. Jayalalithaa also thanked Modi for special allocation of food grains for a period of three months from April to June for Tamil Nadu in keeping with the state's request to continue such special allocations.