Property investor Warner Estate has seen the value of its assets fall by 3% since September but has increased rental income.

Shares in the group slipped 1.5p to 316.5p on Friday morning on the trading update, which took a cautious tone towards financial market conditions.

Warner's net asset value (NAV) per share has slipped by 25.5p to 740.5p. Of this, 22p relates to the funds and balance of its share in the Greater London Office joint venture.

A full valuation of all properties will be undertaken on 31 March.

Debt costs have fallen and borrowing facilities have been renegotiated.

Stockbroker Landsbanki has revised its NAV forecast downwards for 2008 from 10% to 12% decline. 'The shares now trade at a 39% discount to NAV in 2008 and 41% for 2009,' said analyst Mark Reed.

'We leave our dividend forecast unchanged at 23.0p and 24.2p for 2008 and 2009 respectively, which implies a very attractive yield of 7.2%. The dividend looks secure given its cost is around£12m, which can be funded from within existing facilities and or modest asset disposals and the requirements of the REIT for a 90% payout.'