By Lucy Craymer

WELLINGTON (Reuters) - New Zealand's central bank on Wednesday delivered its seventh straight interest rate hike and signalled a more hawkish tightening path over coming months to restrain stubbornly high inflation.

The aggressive tone of the Reserve Bank of New Zealand's (RBNZ) statement warning of future hikes being brought forward lifted the local dollar and pushed swap rates higher.

The RBNZ raised the official cash rate (OCR) by 50 basis points to 3.0% as expected, a level not seen since September 2015, and crucially, it now sees rates at 4.0% by early next year, compared to a previous projection of 3.7%.

Wednesday fourth straight 50-bps hike, along with earlier smaller increases that lifted the cash rate from a record low of 0.25% in October, marked the most aggressive tightening by the central bank since 1999.

"It remains appropriate to continue to tighten monetary conditions at pace to maintain price stability and contribute to maximum sustainable employment," the central bank said in a statement.

The RBNZ also increased the projected peak for the cash rate to 4.1% where it expects it to remain into 2024.

"The overall tone of the policy assessment was hawkish. Inflation remains the focus," ANZ bank economists said.

Markets were quick to price in the more aggressive outlook.

Bank bill futures for March slid 13 ticks to 95.76, while two-year swap rates rose 6 basis points to a three-week top of 3.97%. The New Zealand dollar rose 0.4% to $0.6360.

"It's hawkish compared to expectations, in both raising the OCR track and the tone," said Imre Speizer, head of NZ Markets Strategy at Westpac.

"They're more worried about the labour market, that's sticking out. They put a new sentence in there to say inflation remains too high and the labour market remains too tight."

COST PRESSURES

All 23 economists polled by Reuters had expected the central bank's policy committee to lift the cash rate by 50 basis points, but there was some division about where rates would peak and if it might need to cut them next year.

"Committee members agreed that monetary conditions needed to continue to tighten until they are confident there is sufficient restraint on spending to bring inflation back within its 1-3% per annum target range," the central bank said.

Inflation has been running at three-decade highs hitting 7.3% in the second quarter even though the RBNZ has been a front-runner among central banks in withdrawing pandemic-era stimulus.

In the first quarter, New Zealand's economy unexpectedly contracted due to a surge in COVID-19 cases and growth is expected to be restrained over coming quarters due to tightening financial conditions.

The RBNZ's statement on Wednesday reinforced its priority was on preventing inflation from getting out of hand even at the expense of growth.

"The war in Ukraine has put upward pressure on global commodity prices, especially oil and food, and disrupted global trade," the central bank said.

"Lockdowns in some Chinese cities to combat the spread of COVID-19 has contributed to supply-chain bottlenecks and shipping times and costs remain elevated."