(Reuters) - Northern Ireland plans to cut 20,000 public-sector jobs over four years as part of a bid to put the province's finances on a more sustainable footing, the region's finance minister said on Monday.

The cuts, out of the province's total workforce of 820,000, are part of a wide-reaching political agreement reached in December that paves the way for Northern Ireland to cut its corporate tax rate to better compete with the Republic of Ireland for foreign direct investment.

The Northern Ireland government hopes to make the job cuts through voluntary redundancies and a hiring freeze rather than layoffs.

December's Stormont House agreement "outlined our agreement to reduce the public-sector workforce in Northern Ireland by 20,000 posts over the next four years through a combination of measures such as a Voluntary Exit Scheme and recruitment freezes," the province's finance minister, Simon Hamilton, told the region's parliament on Monday.

The measure was not widely publicized by the parties when the agreement was secured in December.

"This budget and the agreement that has been reached on welfare reform puts the executive’s finances back on a long-term and sustainable basis," Hamilton said in the speech to the region's parliament on Monday. "It also paves the way for allowing Northern Ireland to set our own rate of corporation tax."

Northern Ireland has been under pressure to cut its dependence on a 10 billion-pound annual grant from London to run its public services.

The British government has said that if Northern Ireland makes the required budget cuts it will be allowed to cut its corporate tax rate from its current 21 percent for some foreign companies to closer to Ireland's 12.5 percent.