Cash-strapped Greece on Sunday introduced a tax-free threshold on small gambling winnings, as it tries to increase tax receipts from gambling monopoly OPAP without hurting its sales.

According to a legislative amendment to be submitted to parliament soon, OPAP players' winnings will be taxed progressively, the finance ministry said. The move scraps a 10-percent flat rate on all winnings which was announced in September as part of government efforts to plug its budget deficit.

Winnings between 100 and 500 euros will be henceforth taxed at 15 percent and those above at 20 percent, the Finance Ministry said. Winnings below 100 euros will go entirely tax free.

Analysts had criticized the flat-rate taxation, arguing it would discourage small-time punters and hurt company sales and tax receipts.

Thirty-four-percent state-owned OPAP is one of Europe's biggest gambling companies and the crown jewel in the debt-laden country's privatization program. It is worth 2 billion euros on the Athens Stock Exchange, making it Greece's third-biggest company by market value.

OPAP, however, is dogged by regulatory uncertainty, with rivals such as William Hill and Stanleybet challenging its monopoly and taxation regime in Greek and European courts. Regulatory and taxation news frequently cause wild swings in its share price.

The government said on Sunday it obtained European Union approval to scrap the flat tax rate. A 30-percent levy on OPAP gross earnings, also announced in September, is not changing. [Reuters]