* Aussie shares down 0.3 pct
* Ex-dividend trading CBA erases gains in healthcare and industrials
* NZ at three-month closing low
* Fletcher Building plunges after flagging bigger loss (Updates to close)
Feb 14 (Reuters) - Australian shares fell 0.3 percent on Wednesday as trepidation ahead of key U.S. inflation data and losses in Commonwealth Bank of Australia CBA.AX , which traded ex-dividend, eclipsed gains in healthcare and industrial stocks.
The S&P/ASX 200 index .AXJO fell 0.3 percent or 14.7 points to 5,841.2, following a 0.6 percent rise on Tuesday.
Investors were cautious ahead of U.S. inflation data due later in the global day that could either upset Wall Street's fragile recovery or clear the way for additional gains. N
Global equity markets largely remained volatile after a brutal selloff recently, which was triggered by anxiety over expectations of higher inflation and interest rates.
A mixed bag of earnings also kept Australian equities subdued.
CBA led the decline with a 3 percent drop as it traded ex-dividend. Others in the 'Big Four' traded marginally lower, while National Australia Bank NAB.AX rose 0.4 percent.
A government-backed inquiry into the country's finance sector, rocked by scandals including interest rate rigging and alleged money laundering, has put enders under pressure. The inquiry on Monday said it will start its year-long investigation by scrutinising banks' mortgage selling tactics. chain Domino's Pizza Enterprises Ltd DMP.AX said half-year profit rose 17 percent, but missed market expectations, sending shares down 6.1 percent. stock Telstra Corporation Ltd TLS.AX slipped 1.4 percent.
On the brighter side, healthcare giant CSL Ltd CSL.AX jumped as much as 6.2 percent to a record high after it said first-half profit climbed 35 percent and upgraded its earnings guidance for the full year. of CSL pared some of those gains to finish the session up 5.1 percent.
Insurance Australia Group IAG.AX rose 3.2 percent to a record close after clocking a 24 percent jump in half-year net profit. Zealand's benchmark S&P/NZX 50 index .NZ50 fell 0.8 percent or 63.42 points to settle at 8,058.8 - its weakest close since Nov. 16. The index fell for a sixth session in seven.
Fletcher Building FBU.NZ , New Zealand's biggest construction company, accounted for most of the losses on the index, plunging 9.3 percent to finish at its lowest since Dec. 7.
The builder said it expected its embattled commercial building unit to post a NZ$660 million ($480.22 million) loss in fiscal 2018, pushing its shares down as much as 13.8 percent - its biggest intraday drop in nearly two decades.