Net Asset Value(s)

British Portfolio Trust PLC
15 December 2006

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 14 December
2006:

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 185.63p.

2)   based on the market value of the company's fixed interest rate swap 
     contracts, the capital net asset value per ordinary share was 185.55p and

3)   based on the number of shares held in treasury, the net asset value per 
     ordinary share was 185.00p.

The market value of the company's fixed interest rate swap contracts is updated
monthly.

Enquiries:
Peter Ingram
Tel: [phone]
15 December 2006





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