* Aussie shares close at highest since March 22
* Miners lead, banks cap gains
* NZ up on dairy, industrial boost (Updates to close)
April 18 (Reuters) - Australian shares rose 0.3 percent on Wednesday, buoyed by mining shares, but gains were capped by losses in banking and healthcare stocks.
Robust earnings on Wall Street in what is expected to be the strongest earnings season in seven years also provided the regional market with a confidence boost. MKTS/GLOB
The S&P/ASX 200 index .AXJO rose 19.9 points to 5,861.4, its highest close since March 22. The benchmark was flat on Tuesday.
Miner South32 Ltd S32.AX was the top boost to the index, up 2.5 percent.
Iron ore and steel prices in China rallied following a surprise cut in banks' reserve requirements on Tuesday, and as mounting worries over tighter supply following U.S. sanctions on key producer Rusal pushed London aluminium futures to their strongest level since 2011. IRONORE/ MET/L
Steel manufacturer BlueScope Steel BSL.AX climbed 4.1 percent, while global miner Rio Tinto (LON:RIO) RIO.AX rose 1.1 percent after reporting a rise in first-quarter iron ore shipments. Petroleum WPL.AX climbed 1.1 percent after it said increased output and higher liquefied natural gas prices drove up first-quarter revenue 30 percent. machine maker Aristocrat Leisure ALL.AX rose 2.5 percent.
Financials and large-cap healthcare stocks fell, however.
Commonwealth Bank of Australia CBA.AX slipped 0.5 percent, while healthcare giant CSL Ltd CSL.AX fell 0.7 percent.
CBA said on Tuesday it plans to list its investment management business this year, at a time when lenders are being investigated by a powerful judicial inquiry and face scrutiny from authorities. Treasurer Scott Morrison warned on Wednesday that financial sector executives responsible for widespread breaches of corporate law could face jail. New Zealand, the benchmark S&P/NZX 50 index .NZ50 rose 0.3 percent or 24.97 points to 8,369.49.
Dairy firm a2 Milk Company ATM.NZ rose 1.3 percent, while Auckland International Airport AIA.NZ was up 1.2 percent.
Fisher & Paykel Healthcare Corporation FPH.NZ fell 1.4 percent lower to its lowest close since mid-Sept.