* Comedian-turned-president's new party set to win

* He won April's presidential race by a landslide

* Offers coalition talks to rock star Vakarchuk's party

* Says priorities are ending war and fighting corruption (Updates with early counting, adds quotes, details)

By Matthias Williams and Natalia Zinets

KIEV, July 21 (Reuters) - Ukrainian President Volodymyr Zelenskiy's party took a commanding lead in Sunday's snap parliamentary election, consolidating the power of the novice politician whose stunning rise has upended traditional politics in the war-scarred nation.

A former comedian who played a fictional schoolteacher-turned-president in a popular TV series, the 41-year-old Zelenskiy has tapped into widespread voter anger over corruption and low living standards in one of Europe's poorest countries.

Sunday's likely victory would give him control of parliament and the formation of a new government, handing him a stronger mandate to implement reforms after he won the presidential election in April by a landslide.

Exit polls and early counting of the results showed him far ahead of all other parties, although possibly short of a majority, prompting him to offer coalition talks with a pro-Western party, Voice, fronted by rock star Sviatoslav Vakarchuk.

"We will not let Ukrainians down," Zelenskiy said at his election headquarters after the exit poll results were released.

"You know our main priorities ... they are the same as those of every Ukrainian, I'm sure - to end the war, secure the return of our prisoners and victory over the corruption that still remains in Ukraine."

On taking office, Zelenskiy had to deal with a Cabinet and lawmakers mostly loyal to his predecessor, Petro Poroshenko, prompting him to announce on the day of his inauguration a snap election to win a mandate in parliament.

Exit polls showed his new Servant of the People party with by far the most votes. The Russian-friendly Opposition Platform was in a distant second place, followed by Poroshenko's party and that of a former prime minister, Yulia Tymoshenko.

Vakarchuk's Voice party was fifth.

"We invite Mr. Vakarchuk to talk," Zelenskiy said.

"I think that the post of the Ukrainian prime minister - I will repeat - must be occupied by a new face, a person who specialises in economics," he added.

After Zelenskiy's offer, a senior member said Voice was open to an alliance with new political forces so long as they were not backed by oligarchs.

FIRMER GRIP

The election gives Zelenskiy a firmer grip on a country at the centre of a standoff between Moscow and the West, arising from Russia's annexation of Ukraine's Crimea peninsula in 2014 and role in a conflict in eastern Ukraine that has killed 13,000 people in the past five years.