German energy giant RWE on Monday confirmed its optimistic forecast for 2017, reporting a "good" start to the year, thanks also to its renewables subsidiary Innogy.

RWE said in a statement that net profit grew by 10 percent to 946 million euros ($1.03 billion) between January and March compared with the same period last year.

But revenues fell 2.7 percent to 13.3 billion euros in the first quarter, while adjusted operating, or underlying profit fell 6.5 percent to 2.1 billion, as income from electricity generation slid.

RWE said it remains confident of achieving its forecast of boosting adjusted net profit to between 1.0 and 1.3 billion euros over the full year, compared with 800 million in 2016.

Full-year operating profit should range between its 2016 level of 5.4 billion euros and a slight improvement to 5.7 billion, it said.

RWE, based in Essen, western Germany, owns Europe's largest stable of coal-fired power plants, leaving it especially vulnerable to subsidised competition from renewables as the country commits to an "energy transition".

Like rival EON, RWE spun off its renewables and power grid businesses under a new name, Innogy, while keeping its coal, gas and nuclear plants within the original company structure.

Innogy, listed on the Frankfurt stock market but still majority-owned by RWE, on Friday reported a first quarter in line with expectations.

While a lack of wind this winter weighed on its income from renewable generation, the grid business bolstered Innogy's bottom line in the first three months, allowing it to confirm its forecast of 1.2 billion euros in adjusted net profit for the year -- slightly up from 2016's result.