A Dublin city centre office block, O'Connell Bridge House, which was rented by the Government until last January at £6.96 per sq ft, is back on the market with the letting agent seeking rents of £45 to £50 per sq ft. The new rent level is the highest being sought in the city for an entire block.

Property developer John Byrne has spent around £10 million on a major refurbishment of the building since the Department of the Environment vacated it after their 35-year lease ran out at the beginning of the year.

Agent Jones Lang LaSalle says there is "lots of interest" in the block which will be let on a sliding scale, starting at £45 a sq ft for floors one to six, £48 for floors seven and eight, and £50 for the ninth and tenth floors. A rent has not yet been announced for the penthouse on the eleventh floor, which was originally used as a restaurant and bar.

Architect Brian O'Halloran, who handled the refurbishment, says "no expense was spared to do a really good job on the block", which was now one of the best in the city. A new double glazing system with polished aluminium cappings has been installed to replace single glazing which was in use for 35 years. Internally, the 64,644 sq ft office building has been completely refitted with raised access floors, dropped ceilings and air conditioning. The tenth floor is being fitted out as a boardroom, keeping the original wooden floors. It has superb views over much of the city.

Although the Office of Public Works vacated the building, it has since agreed to rent another block being developed by Mr Byrne at Smithfield. The 70,000 sq ft Phoenix House nearing completion is to be occupied by the Courts Services Board at a rent of £27 per sq ft.

The OPW has managed to lease several buildings in recent months at under £30 per sq ft, and although it is expected to take additional space in the future, it will not be returning to O'Connell Bridge House. A spokesperson said that the quoting rents of £45 to £50 per sq ft were "too rich for our blood." The OPW's office requirements will not be determined until the much delayed decision on decentralisation is taken by the Government.

Office rents in Dublin have been steadily moving up over the past year because of the immense shortage of space in the city centre. Hamilton Osborne King is quoting a rent of £50 per sq ft for a short term letting of 4,000 sq ft on part of the first floor of Styne House at Upper Hatch Street. The same space was originally let last February at £33 per sq ft.

Meanwhile, Palmer McCormack has secured a rent of £40.41 per sq ft for 12,497 sq ft of space on a long lease at Osborne House on Earlsfort Terrace. Stockbrokers Dolmen Butler Briscoe are the new tenants, replacing Guinness Mahon.

Also in the city centre, Jones Lang LaSalle is understood to be close to renting 7,000 sq ft in Hardwicke House at Hatch Street at a rent of £45 per sq ft. The developer, Hardwicke, let most of the building last year for rents around £35 per sq ft.