ESAT Digifone, the Irish-Norwegian consortium which is to outrun the State's second mobile telephone system, is to set up its headquarters in the former Bord na Mona building at Lower Baggot Street, Dublin 2. The company is to occupy 24,000 square feet on the ground, first and second floors under a 25year lease which provides for a break option around the 12th year. The rent is thought to be in excess of £15 per square foot.

It is understood that ESAT has not yet completed formal contracts to take the space. Bord na Mona's letting agent, Sherry FitzGerald, refused to confirm terms have been agreed for the three floors.

Another company is to decide shortly whether to occupy the two top floors of the 40,000-square-foot building, which was recently refurbished by Bord na Mona at a cost of over £2 million. The upgrading also included replacing the glass-panelled walls, which were leaking.

The board is expected to offer the block for sale once the new leases have been signed. The building will produce a rent of £665,000 if the rents are fixed at £15 per square foot and the 60 car-parking spaces let at £1,000 each. In the event of the block going on the market, the yield may well be between 7 and 7.5 per cent. This equates to a price of £8.2 million and £8.75 million.