The Sixth Pay Commission on Monday recommended a hefty increase in salaries of over four million Central Government employees, a move that would cost the exchequer Rs 12,561 crore in 2008-09. The Commission, headed by Justice B N Srikrishna, submitted its report to Finance Minister P Chidambaram recommending implementation of the revised pay from January 1, 2006, which would impose an arrear payout burden of Rs 18,060 crore on the government.