Net Asset Value(s)

NET ASSET VALUE

BRITISH PORTFOLIO TRUST PLC

The unaudited net asset values for British Portfolio Trust plc. at close of
business 3 April 2012 was:

143.49p Capital only (undiluted)
141.83p Capital only (Diluted for treasury shares)
144.78p Including current year income (undiluted)
142.95p Including current year income (Diluted for treasury shares)

Notes:

1. Investments have been valued on a bid price basis.

2. Revenue items included in net asset value, with dividends payable deducted
on the ex-dividend date.