(Reuters) - A nuclear deal with�Iran�may spur proxy wars in the Middle East as Sunni Muslims try to counter an increasingly wealthy and powerful Shi'ite�Iran, the European Union�s counter-terrorism coordinator said on Monday.

Gilles de Kerchove told the European Parliament one important cause of terrorism was "this war by proxy from the Sunni world which feels a bit on the defensive because of the rise of�Iran".

Asked if a deal to curb�Iran's nuclear ambitions being negotiated in Switzerland would have an impact, he said: "Yes, of course, because�Iran�will have even more money.

"It is a sophisticated country, with a vision, more and more powerful in the Middle East, and therefore on the Sunni side there might be a temptation for some to support extremist groups to fight against�Iran�by proxy," he said.

Major powers are trying to reach a preliminary agreement with�Iran�aimed at stopping it from achieving the ability to develop a nuclear bomb, in exchange for an easing of sanctions that are crippling its�economy.

Mostly Sunni�Saudi Arabia�is leading air strikes in�Yemen�to try to halt advances byIranian-allied Shi'ite Houthi fighters, the latest front in its widening contest with�Iran�for power in the region.

Their proxy struggle is also playing out in Syria, where Tehran backs Bashar al-Assad's government against mainly Sunni rebels, and�Iraq, where Iranian-backed Shi'ite militias are playing a major role.

By Reuters