Net Asset Value(s)

British Portfolio Trust PLC
20 December 2007



British Portfolio Trust PLC


As recommended by the AIC, financial assets are now valued on a bid price basis
in accordance with revised UK accounting standards.

British Portfolio Trust PLC announces that at close of business on 19 December
2007:


1)      Excluding any profit or loss on the mark to market value of the
company's fixed interest swap contract, the capital net asset value per ordinary
share was 181.60p.

2)      based on the number of shares held in treasury, the net asset value per
ordinary share was 181.31p.



The NAV at market value will no longer be announced as the fair value of the
interest rate swap contracts is now recognised in the financial statements in
accordance with the adoption of FRS26 'Financial Investments: Recognition and
Measurement'.


Enquiries:
Peter Ingram
Tel: [phone]
20 December 2007





                      This information is provided by RNS
            The company news service from the London Stock Exchange