LISBON, May 13 (Reuters) - Portugal's largest utility firm EDP-Energias de Portugal on Thursday posted a 6% rise in recurring profit for the first three months of the year to 159 million euros, driven by the integration of Spanish electricity company Viesgo.

Earlier on Thursday, its renewables energy unit EDP Renewables reported a 39% drop in net profit to 38 million euros and a 19% drop in EBITDA to 445 million euros due to lower wind load factors and the impact of Arctic-like temperatures. "The integration of Viesgo and strong performance of our hydro and supply operations... compensated the adverse weather effects on U.S. renewables," EDP said in a statement. EDP, whose main shareholder is China Three Gorges, agreed to buy Viesgo in July, more than doubling its electricity distribution presence in Spain. The company said its consolidated earnings before interest, taxes, depreciation and amortisation (EBITDA) contracted 12% to 864 million euros, while its recurring EBITDA fell 8% compared to a year ago.

By contrast, its EBITDA in Spain increased 26% to 214 million euros. In the first quarter, 85% of EDP's electricity generation came from renewable energy sources, it said. As of March, 79% of its 23.9 gigawatts (GW) of installed capacity was from renewable sources, with an additional 3.0 GW of wind and solar projects under construction. Its gross investments increased 52% year-on-year to 700 million euros, "of which 93% is allocated to activities fully aligned with the energy transition," the company said. EDP said its net debt rose 7% to 13.1 billion euros from a year ago, "impacted by an increase of working capital investment."

(Reporting by Sergio Goncalves, Editing by Victoria Waldersee and Cynthia Osterman)