Net Asset Value(s)

29 May 2009 M&G High Income Investment Trust P.L.C. The Board of M&G High Income Investment Trust P.L.C. announce that the net asset value at 12:00 noon today was £204.4 million. Income Shares * 43.58p Capital Shares 0.00p Zero Dividend Preference Shares 60.33p Income & Growth Units 43.58p Package Units 103.91p The net asset values have been calculated on a cum-income basis, with dividends payable deducted from net assets on the ex-dividend date. Financial assets are valued on a mid-market price basis. * The ex-income NAV of each Income Shares is 42.26p. ---END OF MESSAGE--- This announcement was originally distributed by Hugin. The issuer is solely responsible for the content of this announcement.