Transurban’s first-half profit has fallen 61.8 per cent to $129 million after its costly acquisition of Sydney’s WestConnex motorway scheme.

Toll revenue rose 14.7 per cent following a 2.7 per cent increase in average daily traffic across the company’s roads, but various expenses and a $163 million increase in depreciation and amortisation pushed profit attributable to security holders down from $338 million a year ago.

Nonetheless, the earnings by which Transurban assesses performance rose 9.8 per cent to $1 billion and the company on Tuesday raised its interim distribution by one cent to 29 cents.

The increase in revenue was driven by a $52 million increase from existing assets – driven by traffic growth across both Australian and North American networks – as well as a $115 million contribution from the acquisition of Montreal’s A25 and its increased stake in Sydney’s M5.

Transurban shares slipped 32 cents, or 2.6 per cent, to $12.14 by 1035 AEDT.