Segro, owner of logistics hub Heywood Distribution Park near Rochdale, said demand for space is holding steady but values continue to decline.
In a trading update, the logistics giant said assets would not be valued again until the end of December but that it expected its portfolio to have continued to fall in value. An interim statement earlier this year said the net asset value had dipped by 10% in the six months ended 30 June.
Segro said IPD figures indicated that industrial property values had dropped by 6.1% in the third quarter of 2008.
On the occupational side, Segro said vacancy rates had moved out only slightly from 9.3% in June to 9.5% in September, simply due to development completions.
Ian Coull, chief executive, said: "Looking further ahead, I believe there will be some very attractive investment opportunities. We are managing the business in a cautious and disciplined manner to ensure that Segro is well placed to take full advantage of such opportunities."
At Heywood, Segro and agents King Sturge and Savills have enjoyed a record year with lettings to Hurley Menswear, JJB Sports, Eddie Stobart, Character Options and Parcelforce.
However, the site is likely to lose two major tenants in the short term with JD Sports and Next both due to leave when leases expire in the next 24 months.