* Financials and miners weigh on benchmark
* RBA expected to stand pat on cash rate
* NZ benchmark index falls up to 1.2%
Sept 1 (Reuters) - Australian shares fell sharply on Tuesday to hit a four-week low, as rising diplomatic tensions with Beijing and a likely recession in the second quarter weighed on investor sentiment ahead of a central bank rate decision.
The S&P/ASX 200 index .AXJO declined 2.4% to 5,914.20 by 0125 GMT, its lowest since Aug. 3, and was on track for a third straight session of losses.
China, Australia's largest trading partner, on Monday launched an investigation into alleged government subsidies of some Australian wine imports. investigation comes amid rising tensions between the two countries after Canberra called for an international inquiry into the origins of the novel coronavirus.
In a meeting later in the day, the Reserve Bank of Australia is likely to hold its cash rate at an all-time low to prop up the economy, which is widely expected to have plunged into recession in the second quarter.
Heavyweight financials .AXFJ were the top drags on the benchmark index, shedding up to 3%. Both Commonwealth Bank of Australia CBA.AX and Westpac Banking Corp WBC.AX lost about 2.5%.
The mining sector .AXMM , heavily reliant on exports to China, fell 2.1% to its lowest since mid-July. Top iron ore miners BHP Group BHP.AX and Rio Tinto (LON:RIO) RIO.AX were the top drags, falling 1.9% and 1.7%, respectively.
Across the Tasman Sea, New Zealand's benchmark S&P/NZX 50 index .NZ50 traded without any disruptions, slipping up to 1.2%.
The New Zealand stock market was hit by a fifth day of cyberattacks on Monday, crashing its website, but maintained trading after switching to a contingency plan for the release of market announcements. Tuesday, financials and healthcare stocks were the top drags, with NZ-listed shares of Australia and New Zealand Banking Group ANZ.NZ losing up to 3%, while Fisher & Paykel Healthcare FPH.NZ shed 4.8%.