OSLO- British renewable energy investor Quercus said it will stop building a 500 million euro ($570 million) solar power project in Iran due to recently imposed US sanctions on Tehran.

The solar plant in Iran would have been the first renewable energy investment outside Europe by Quercus and the world's sixth largest, with a 600 megawatt (MW) capacity.

Sanctions imposed on Iran by the United States earlier this month have already led banks and many companies around the world to scale back dealings with Tehran.

"Following the U.S. sanctions on Iran, we have decided to cease all activities in the country, including our 600 MW project. We will continue to monitor the situation closely," Quercus chief executive Diego Biasi said in an email on Tuesday.

The firm will continue to monitor the situation closely, said Biasi, who declined to comment further.

Construction was expected to take three years, with each 100 MW standalone lot becoming operational and connecting to the grid every six months.

($1 = 0.8773 euros)

(Editing by Terje Solsvik and Alexander Smith) ((lefteris.karagiannopoulos@thomsonreuters.com; +47 23316519; Reuters Messaging: lefteris.karagiannopoulos.thomsonreuters@reuters.net))