Textile firm Arvind Mills today said it would invest Rs 400 crore to expand its retail business in the next four years, to reach the target of being a billion-dollar mark company.The company would be investing Rs 300 crore in large-format retail centres and Rs 100 crore in small stores by opening 30 large retail centres (Megamart outlet) and 200 small format stores (Megamart) across 100 cities in the country by 2012.Around Rs 8-10 crore would be invested in each outlet and the funding would be through the company's internal accruals.Noting that the value of retail market in India was worth about Rs 11,000 crore and was estimated to grow at the rate of 30-40%, he said the company was targeting a turnover of Rs 2,000 crore by 2012 in the retail sector.The company today launched its first 'Megamart Outlet Centre' and was expecting the second Megamart outlet at Pune by May, followed by Hyderabad and Bangalore.About 8 outlet centres and 125 small format stores would be opened by the end of next financial year. The company, presently, has 75 stores across the country.Stating that Megamart would now move to tier-II and III cities, he said stores would soon be opened in Nagercoil, Tirunelveli, Vellore and Trichy in Tamil Nadu.Arvind Mills managing director Sanjay Lalbhai said though the retail division's contribution to the company's turnover was presently only around 8%, it was expected to touch 50% by 2012.