TENANTS should be banging Minerva’s door down. Its futuristic Walbrook development, which boasts 440,000 square feet, is one of the only buildings capable of housing a large tenant within the Square Mile. But it has lost out on some important signings – BlackRock went to Songbird’s Drapers Gardens while Macquarie signed a lease at British Land’s Ropemaker – and things don’t seem to be improving.

Now it looks like Bloomberg is close to signing a pre-let at Legal and General’s Walbrook Square: another one is about to bite the dust. Minerva’s silence on prospective tenants for its largest City development suggests it will be 2011 before a firm moves in.

An ever longer delay would be bad for cash flow, which is already a cause for concern. Cash flow from operating activity was -£45m in 2010, and an empty Walbrook would likely mean a further drain in the region of £10m a year, due to empty rates and service charges.

Minerva is right to point to the stellar growth in its net asset value since. But it doesn’t count for much if those assets are empty.