Telecoms giant BT has brought forward the date of the next contribution to its pension deficit by nine months, pumping more than half a billion pounds into the scheme in March.It had been due to pay the money in December, but decided it was economically beneficial to do so now, utilising existing cash deposits.The BT Pension Scheme has received £505m - the actuarial value of the £525m due to have been paid in December."The payment will be tax deductible at a corporation tax rate of 28%, rather than the 26% which will apply in the 2011/12 financial year, and the timing of the tax deduction will be brought forward to the first half of the 2011/12 financial year," BT said Wednesday. Under a 17-year recovery plan, agreed in December 2008, BT promised to pay £525m per annum for the first three years. There'll be a funding valuation in December.The early payment does not impact the company's previously announced outlook for free cash flow.LW