Downer EDI Ltd. posted a net profit of $87 million in its first-half, 1.9 per cent above the $85.4m it reported the previous year.

The engineer and infrastructure company stuck to its forecast of a 5 per cent growth in net profit for the financial year on Thursday.

The company's profit was just marginally below an average of the forecasts of six analysts collected by Dow Jones Newswires of $88.3m.

Its shares registered a four per cent fall after traders were disappointed by its unaltered full year guidance, despite of the growth in first half profit.

Revenue from ordinary activities for the half was reported to slip by 3 per cent to $2.79 billion from $2.88bn a year earlier and the group revealed an interim dividend of 13.1 cents a share, just above the 13c a year earlier.

Downer EDI reported net profit of $87.037 million for the six months to December 31, up 1.9 per cent from $85.443 million in the previous corresponding period.

"In spite of the half being a little bit stronger than we anticipated... we still think that guidance at around five per cent of NPAT is about right for where we are", Chief Executive Geoff Knox told analysts.