Ukraine enters uncharted new era after comedian wins presidency

* Results show comedian Zelenskiy easily wins presidency

* Outcome is bitter blow for incumbent Poroshenko

* Investors, West and Russia wondering what he will do

* Zelenskiy says win shows anything is possible

* Graphic https://tmsnrt.rs/2EEQ22R

By Matthias Williams and Andrew Osborn

KIEV, April 22 (Reuters) - Ukraine entered uncharted political waters on Monday after near final results showed a comedian with no political experience and few detailed policies had dramatically up-ended the status quo and won the country's presidential election by a landslide.

The emphatic victory of Volodymyr Zelenskiy, 41, is a bitter blow for incumbent Petro Poroshenko who tried to rally Ukrainians around the flag by casting himself as a bulwark against Russian aggression and a champion of Ukrainian identity.

With over 90 percent of the vote counted, Zelenskiy had won 73 percent of the vote with Poroshenko winning just under 25 percent.

Zelenskiy, who plays a fictitious president in a popular TV series, is now poised to take over the leadership of a country on the frontline of the West's standoff with Russia following Moscow's annexation of Crimea and support for a pro-Russian insurgency in eastern Ukraine.

Declaring victory at his campaign headquarters to emotional supporters on Sunday night, Zelenskiy promised he would not let the Ukrainian people down.

"I'm not yet officially the president, but as a citizen of Ukraine, I can say to all countries in the post-Soviet Union look at us. Anything is possible!"

Zelenskiy, whose victory fits a pattern of anti-establishment figures unseating incumbents in Europe and further afield, has promised to end the war in the eastern Donbass region and to root out corruption amid widespread dismay over rising prices and sliding living standards.

But he has been coy about exactly how he plans to achieve all that and investors want reassurances that he will accelerate reforms needed to attract foreign investment and keep the country in an International Monetary Fund programme.

"Since there is complete uncertainty about the economic policy of the person who will become president, we simply don't know what is going to happen and that worries the financial community," said Serhiy Fursa, an investment banker at Dragon Capital in Kiev.

"We need to see what the first decisions are, the first appointments. We probably won't understand how big these risks are earlier than June. Perhaps nothing will change."

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The United States, the European Union and Russia will be closely watching Zelenskiy's foreign policy pronouncements to see if and how he might try to end the war against pro-Russian separatists that has killed some 13,000 people.