* RBNZ cuts rates to 2.75 pct, third consecutive easing
* Cenbank sees some further easing as likely
* RBNZ says further currency fall appropriate, NZD tumbles
* RBNZ says slow-down in China could lead to further rate cuts (Releads, adds comment, details)
By Charlotte Greenfield and Naomi Tajitsu
WELLINGTON, Sept 10 (Reuters) - New Zealand's central bank cut its benchmark interest rate on Thursday and said a further economic slowdown in China, the country's biggest trading partner, could lead to more rate cuts if it weakened growth in the island nation.
The Reserve Bank of New Zealand (RBNZ) cut its official cash rate (OCR) by 25 basis points to 2.75 percent as widely expected, its third cut in as many policy reviews.
"Some further easing in the OCR seems likely," RBNZ governor Graeme Wheeler said in a statement. "This will depend on the emerging flow of economic data."
Weak dairy prices and plummeting business and consumer confidence were weighing on growth, Wheeler said. The RBNZ cut its 90-bank bill forecast to reflect an additional rate cut in the coming months, and reduced its economic growth and inflation forecasts.
Westpac chief economist Dominick Stephens said the RBNZ had foreshadowed the possibility of new lows for interest rates. "It's certainly not what the RBNZ is currently thinking, but alternative scenarios have an unfortunate habit of coming true."
The RBNZ cut its outlook for global growth in its quarterly policy statement, and outlined a scenario where a sluggish Chinese economy might push New Zealand's OCR towards 2.0 percent in the next year - which would be a record low.
"Conditions that probably would be needed to create a recession in New Zealand would be something like China slowing dramatically or perhaps moving into a recession," Wheeler told reporters. "That would certainly create huge problems in Australia and ourselves."
Though most economists believe a gradual and prolonged slowdown in China's economy is more likely, a stock market crash and unexpected yuan devaluation last month have rattled confidence, inside and outside China.
"The big worry would be if China really started to significantly devalue the RMB (yuan)," Wheeler said, estimating China's current growth rate at around 5-6.5 percent, versus the official 7 percent forecast.
"We've seen authorities basically say they want to stabilise the RMB but if there were to be a very substantial depreciation in the RMB it would certainly export deflation around the rest of the world, so everybody is looking closely at China."
The New Zealand dollar NZD=D4 tumbled more than 2 percent to a low around $0.6263 on the rate cut news, heading towards the six-and-a-half-year low around $0.62 it hit last week.
The RBNZ said falls in the New Zealand dollar =NZD helped support some growth, but it needed to fall further to offset to lower commodity prices, particularly for dairy exports.
(Reportiung by Charlotte Greenfield and Naomi Tajitsu; Editing by Lincoln Feast and Eric Meijer)