The board of directors of Housing Development Finance Corporation (HDFC), which met today, approved a proposal to raise up to Rs 3,114 crore by issuing 1.80 crore shares on preferential basis at Rs 1,730 per share to Citigroup Strategic Holdings Mauritius and CMP Asia (The Carlyle Group).According to a release issued by HDFC to the BSE today, the holding of Citigroup will move up to 9.55% after the issue from the current level of 9.15%, and Claryle Group will hold 5.63%. The meeting also approved a proposal to increase authorised share capital of the corporation from Rs 275 crore consisting of 27.5 crore equity shares of Rs 10 each to Rs 325 crore consisting of 32.5 crore equity shares of Rs 10 each.The money would mostly be used to buy shares of its subsidiary, HDFC Bank, and invest in the life insurance subsidiary. The preferential allotment to Citigroup is being made to ensure the US financial services group's stake in the mortgage lender remains at 12.3% after the allotment to Carlyle.