TBILISI (Reuters) - Georgia's ruling party on Tuesday selected Bidzina Ivanishvili, a billionaire ex-prime minister who is widely believed to be the country's most influential figure, as its lead candidate for a parliamentary election on Oct. 26, Georgian media reported.

Ivanishvili served as prime minister from 2012-2013 and has been honorary chairman of the ruling Georgian Dream party since December.

Current prime minister and close Ivanishvili ally Irakli Kobakhidze was designated the party's number two candidate, Georgian media said.

Ivanishvili has played a major role in an extended political crisis in Georgia around a law on "foreign agents" pushed through by his government earlier this year, amid some of the largest protests seen in Georgia since it won independence from the Soviet Union in 1991.

The United States and other Western nations expressed concern about that law, which requires organisations that receive more than 20% of their funding from abroad to register as "agents of foreign influence".

In a rare public speech in April, Ivanishvili lashed out against the West, saying the foreign agent law was necessary to defend Georgian sovereignty against attempts by a "global war party" to drag Georgia, which is a candidate for European Union membership, into confrontation with Russia.

Both Western and domestic critics have accused Ivanishvili and governments led by his allies of authoritarian tendencies, and of distancing Tbilisi from traditional partners in Western capitals.

Polls show that Georgian Dream remains the country's single most popular party ahead of the October election.

(Reporting by Felix Light; Editing by Gareth Jones)