Mapeley, the Guernsey-based property investment and outsourcing company, revealed a drop in net asset value of 23% in 2007 owing to a £148.6m loss through revaluation of its property portfolio. Financial Times, The Times, Daily Telegraph

Its share price lost 147p to close at £16.19 yesterday, wiping off some of the gains made at the end of last month after it revealed talks with a potential buyer, understood to be Fortress, the US hedge fund and its majority shareholder. The company, which confirmed that talks were continuing, reported a sharp drop in valuation of its properties. This dragged its net asset value to £18.62 a share from £24.23 a share in 2006, in spite of an 8.4% rise in revenue to £417.4m for the year to the end of December.

Mapeley made a pre-tax loss of £129m, compared with a £42.8m pre-tax profit in 2006, but pointed to funds from operations, which it says are the key measurement of operating success, rising 23.4% to £56.4m for the year.

Mapeley said last month that it had received an unnamed takeover approach, thought to be from US investment house Fortress.