New Star Asset Management has been forced to write down the value of its flagship UK property portfolio by a further 8.2% following a drop of a tenth in the four months to November, as a slump in UK commercial property prices takes its toll on retail investors.

In a statement published yesterday, the firm said that the New Star UK Property Unit Trust's valuation reflected the recent deterioration in sentiment towards the commercial property market. The fund's valuer CB Richard Ellis yesterday reduced the value of the portfolio by 8.2%, after an earlier drop of 9.6% in the four months since the end of July.