COPENHAGEN, Aug. 15 (Xinhua) -- Vestas lowered its full year sales guidance for 2018 here on Wednesday after a drop in operating profit during the first half of the year.

Vestas' operating profit for the first six months of 2018 fell 21.4 percent to 385 million euros, down from 490 million euros for the same period last year, it said in the interim financial report.

Net profit declined 17.3 percent year-on-year to 286 million euros, while sales revenue down 3.3 percent to 3.95 billion euros in the first six months.

For the second quarter alone, revenue amounted to 2.26 billion euros, which was on par with second quarter of 2017.

Vestas said the second quarter of 2018 reflected a negative impact of 135 million euros compared to second quarter of 2017, from foreign exchange effects, which primarily stemmed from the US dollar.

The value of the combined backlog of wind turbine orders and service agreements stood at 23 billion euros as of June 30, 2018.

Vestas now expects its revenue for 2018 to reach in the range between 10 billion euros and 10.5 billion euros, as opposed to a previously forecast of 10 billion euros to 11 billion euros.

It also expects to achieve an EBIT margin of 9.5 to 10.5 percent compared to previously 9 to 11 percent.

It added the adjustments are based on improved visibility for the remainder of the year.