British Land saw the value of its property portfolio fall to £8.18bn in the first quarter but said the pace of decline has slowed markedly.The group, which has been the subject of intense bid speculation, said £3.2bn (39%) of assets either increased (£1.7bn) or are unchanged (£1.5bn) in value since March 2009.The overall value of British Land's portfolio declined to £8.18bn compared with £12.29bn previously, though the drop is not as steep as analysts had feared. NAV per share was down 9% to 361p.Underlying pre-tax profit dropped 14.9% to £63m, reflecting property disposals and reduced capitalised interest on development, while net rental income fell to £143m from £162m.'These results demonstrate that British Land remains in a relatively strong position with resilient income from a well-let, prime portfolio,' said chairman Chris Gibson-Smith.'Our financial flexibility and scale give us competitive advantage to capitalise on opportunities.'The group did not comment on reports in the Times this morning that American private equity giant Blackstone is set to buy half of the group's Broadgate development in London's financial district.