RBNZ holds OCR at 2.50 pct RBNZ says headline inflation low RBNZ...

• RBNZ holds OCR at 2.50 pct
• RBNZ says headline inflation low
• RBNZ says some further policy easing may be required

(Adds detail, analyst comment, market reaction)

WELLINGTON, Jan 28 (Reuters) - New Zealand's central bank kept interest rates steady as expected on Thursday but said more easing may be needed due to low inflation.

The Reserve Bank of New Zealand left the Official Cash Rate unchanged at 2.50 percent after cutting four times last year.

"Some further policy easing may be required over the coming year to ensure that future average inflation settles near the middle of the target range," it said in a statement.

"We will continue to watch closely the emerging flow of economic data."

The renewed emphasis on possible future easing was a turnaround from its December statement when it cut its benchmark official cash rate to a record low of 2.50 percent but virtually shut the door on any more rate cuts, saying it expected to achieve its inflation target without more monetary stimulus.

Recent data showed annual inflation at 0.1 percent in the fourth quarter – the lowest since 1999 - raising the stakes for the central bank, which is mandated with keeping inflation between 1 percent and 3 percent.

"It's clearly a more dovish statement that reflects the way that inflation keeps undershooting their forecasts," said Su-Lin Ong, senior economist at RBC Capital Markets.

"It's also likely intended to keep downward pressure on the NZ dollar. We had rate cuts pencilled in for March and June, and this statement only supports that call."

On Thursday the bank emphasized that headline inflation remains low. While it is expected to increase over 2016 it will "take longer to reach the target range than previously expected," it said.

It did note, however, core inflation - which excludes temporary price movements - is consistent with the target range at 1.6 percent.

The central bank also said there are many risks around its outlook, related to global growth, particularly around China, global financial market conditions, dairy prices, net immigration and pressures in the housing market.

It said that house price inflation in the largest city of Auckland "remains a financial stability risk" and that house price pressures have been building in some other regions.

It noted that in recent weeks there has been some easing in financial conditions, as the New Zealand dollar and market interest rates have declined. However, "a further depreciation in the exchange rate is appropriate given the ongoing weakness in exports prices."

The New Zealand dollar fell as far as $0.6424 , after the RBNZ statement from around $0.6480. It last stood at $0.6441.

All economists polled by Reuters had expected the Reserve Bank of New Zealand (RBNZ) to remain on hold. [NZ/POLL]