PRAGUE (Reuters) - Billionaire Czech Finance Minister Andrej Babis's ANO party has jumped in voter ratings following its victory in regional elections this month, widening its lead over the ruling Social Democrats a year before national polls.

Stem agency's October opinion poll, released on Monday, indicated the ANO would win 29.7 percent of the vote, up by more than five percentage points from a month ago and well ahead of Prime Minister Bohuslav Sobotka's Social Democrats, which slipped to 14.4 percent from 20.7.

The drop in support for Sobotka's leftist party, which narrowly beat the ANO in the last national election in 2013, was the biggest since it came to power in early 2014.

It fell to third place in Stem's poll, behind the Communist party, the third biggest group in parliament, which edged up a touch to 14.6 percent.

The governing coalition's third member, the Christian Democrat party, was steady at 6.7 percent.

The coalition is entering its final year with a growing economy, the lowest unemployment in the European Union and a budget set to be balanced for the first time in two decades.

But the movement started by Babis five years ago has appealed to voters with a campaign against corruption and a business-like approach to government.

Babis owns a conglomerate of over 250 companies, from farming to chemicals and media, and has faced criticism for potential conflicts of interest.

The Stem poll suggested his party would win 78 of the 200 seats in the lower house, meaning it could almost certainly form a ruling coalition.

The Social Democrats would claim 34 and the Communists 33. On the right, the former ruling Civic Democrats would win 21 seats and conservative party TOP09 would get 15. The Christian Democrats would hold 14.

(Reporting by Jason Hovet; editing by Andrew Roche)