Debenhams is suing Grosvenor for failing to open Liverpool One on time, the developer confirmed as it revealed the scheme's value has fallen by £48.8m.
The retailer is seeking damages of £125,000 a week from its "notified" opening date of 31 March until the 190,000 sq ft store opens.
Grosvenor says the 31 March date was an error and the correct date should have been that of the first phase opening on 29 May.
Grosvenor issued a statement that said: "We are defending a claim brought by Debenhams in connection with the opening of their new store in Liverpool One. The first phase opening of the development will be on 29 May. Working relations between Debenhams and Grosvenor remain very good and as one of the two flagship department stores along with the new John Lewis, Debenhams will make an important contribution to Liverpool One's retail offer."
Grosvenor's annual results today showed a further £48.8m provision against the 2.4m sq ft Liverpool One, to reflect the "decline in capital values during the year".
Last year, Grosvenor reported a £140m cost over-run on the £1bn scheme but today denied speculation there would be further such hits announced when the full annual report is published in the coming weeks.
Excluding the Liverpool One provision, revenue profit increased by an underlying 82% to £112.9m during 2007. Grosvenor's balance sheet net asset value increased by 19% to £3.1bn during 2007.
On a global level, the Duke of Westminster's group performed well and Grosvenor Australia achieved a particularly high total return of 24.8%.
Profits before tax increased by 3.0% to £524.0m and the group earned a total return of 14.4%, down from 15.5% in 2006.
Total assets under management, both for Grosvenor and other investors, increased by 17% to £12.9bn during the year.
Mark Preston, currently chief executive of Grosvenor Britain & Ireland, will take over as group chief executive on 1 July 2008. Jeremy Newsum will remain on the group board as a non-executive director.