ATHENS (Reuters) - Greece's ruling conservatives have widened their lead over anti-austerity opponents, three polls showed, in a sign that improving business sentiment has bolstered support for the crisis-ridden country's government.

A survey by GPO pollsters for Mega TV released on Tuesday put support for the New Democracy party at 21.3 percent, 1.8 percent ahead of the leftist Syriza party, which opposes Greece's international bailout.

Two polls published on Sunday by agencies RASS and ALCO showed Prime Minister Antonis Samaras' conservatives leading by as much as 2.8 points, up from about 1 point last month.

This is New Democracy's widest poll lead since an election victory last year that made it the backbone of a three-party coalition dedicated to renewing Greece's EU/IMF bailout and saving it from bankruptcy and a chaotic exit from the euro zone.

Bond and share prices have rebounded since then, with the stock market hitting a two-year high two weeks ago and Samaras saying Greece is on course to meeting its EU/IMF targets.

However, the Greek economy remains stuck with a record unemployment rate of 27 percent and a harsh recession.

Despite the improved ratings, a rift has emerged within the coalition over a draft anti-racism bill aimed at stopping violence against immigrants that activists blame on sympathizers of the far-right Golden Dawn party.

The bill, sponsored by the coalition's two junior partners, the Socialist PASOK and Democratic Left parties, proposes penalties ranging from fines to withdrawal of voting rights for those inciting racial hatred or carrying out attacks.

The bill targets Golden Dawn, which tapped into popular anger over austerity-driven cuts to emerge from obscurity and enter parliament in last year's election. PASOK backs the bill whereas New Democracy opposes it, saying existing laws suffice.

After inconclusive talks on the bill on Monday, PASOK chief Evangelos Venizelos said he would not back down.

"We have a political formation which is blatantly Nazi," he said. "It's our international duty... to have full-fledged legislation against pro-Nazi and violent, racist behavior."

Golden Dawn, which denies any involvement in anti-immigrant attacks, ranked third with 10 percent in the GPO poll.

(Reporting by Renee Maltezou; Editing by Harry Papachristou and Mark Heinrich)