The new tax comes as Paddy Power (>> Paddy Power plc) and other major bookmakers such as Ladbrokes (>> Ladbrokes PLC) and William Hill (>> William Hill plc) grapple with tighter regulation and additional taxes in Britain, including duties on online betting and high-stakes gambling machines.

Ireland first announced plans to bring online operators into the tax net in 2011, proposing that the 1 percent tax on bets placed in shops be extended to wagers made online or over the telephone from customers based in Ireland.

The legislation has been delayed a number of times but will commence once operators who are already licensed in another jurisdiction are granted licences to provide betting services in Ireland.

A spokeswoman for the finance department said it expects that operators would begin to pay the tax by the middle of this year.

Paddy Power, Ireland's largest bookmaker, earns more than three quarters of its profit online and has said the tax would have cost it 8 million euros (5.8 million pounds) last year. Its profit before tax for 2014 was 167 million euros.

The company said this week that its effective tax rate would be pushed into the high teens from 13 percent.

"Where Ireland and the UK are at right now, it seems to have hit a balance. The big increases we think are set for a while," Paddy Power Chief Financial Officer Cormac McCarthy told a news conference on Wednesday.

(Reporting by Padraic Halpin; Editing by David Goodman)

Stocks treated in this article : Paddy Power plc, Ladbrokes PLC, William Hill plc