National Toll Roads' profits fell to €4.6 million (£3.62 million) in January-June, from €6.6 million in the same period last year.

This was despite a 136 per cent expansion in revenues, which grew to €38.2 million from €16.5 million in the period. Earnings per share fell 29.8 per cent to 20.5 cents and an interim dividend was set at 8.2 cents per share.

The road, waste and wind energy group attributed the fall in profits, which it signalled early this year, to higher municipal rates and investment costs, mainly for the development of a second West Link bridge in Dublin.

Citing the expansion of its wind and waste operations, the group's chief executive, Mr Jim Barry, said it had made "huge progress . . . The mix of the business has changed pretty fundamentally."

The group's six-month revenues included €13.9 million from its waste operations and €11.2 from Eirtricity, the wind energy firm in which it has a 51 per cent stake.

Toll income from the West Link bridge rose 4 per cent to €15.9 million following a 4.2 per cent rise in traffic volume to 12.4 million vehicles. But municipal rates rose to €2.9 million from €400,000 in the period, hitting profits.

Construction of the second West Link bridge commenced last month. The two-year project will cost €22 million.

Income from the East Link Bridge in Dublin was constant at €3.6 million, although volumes fell 5.3 per cent to 3.6 million vehicles. Mr Barry said the fall was due to traffic congestion in the north city.

West Link tolls which were agreed with the National Roads Authority increased on September 1st, reflecting the imposition of VAT following a European Court ruling and an agreement to fund the second bridge. The charge per car travelling on the West Link bridge rose to £1 from 80p.

The equivalent charge for the East Link bridge rose to 85p from 70p under a concession agreement with Dublin Corporation.

Tolls will rise marginally again next January when those rates are converted into euros, and when notes and coins for the single currency are introduced.

Increases to €1.30 instead of €1.27 on the West Link and to €1.10 instead of €1.08 on the East Link reflect bye-law provisions allowing the firm to round up euro conversions to the nearest 10 cents.

Mr Barry said a 30 per cent pay award to bridge workers last May was "not material" from a group perspective. After-tax losses at Eirtricity rose to €900,000 in the half-year, from €300,000.

National Toll Roads completed the acquisition last Friday of a 76.9 per cent stake in Celtic Utilities, its joint venture partner in Celtic Waste, which made an after-tax profit of €1.2 million in the period.

Another joint venture to construct the Kilcock-Kinnegad and Waterford bypass projects was short-listed for public-private partnerships in the National Development Plan.