Legal & General is to launch proceedings to help force Metrovacesa to finalise acquisition of the 1m sq ft Walbrook Square development in the City.

The Spanish developer agreed to buy the site for £240m in September last year with a promise that it would build at least one of four planned buildings.

Today's Finacial Times reports that even at the end of a heady property boom, the price was seen by the industry as high.

Since the deal was agreed, commercial property values in the City have plummeted. Prices of development land almost halved in the second half of last year, agent Knight Frank estimates.

Commercial property agents say the Walbrook Square site is now worth far less on paper than the £240m Metrovacesa offered when the sales process began.

The purchase was conditional on L&G’s meeting a series of conditions.

The fund manager will go to the High Court to secure recognition that it is meeting disputed points after almost eight months of wrangling.

L&G confirmed that it was seeking clarification from the High Court of the meaning of a clause in the contract for the sale of its leasehold interest in Walbrook Square to Metrovacesa.