* Aussie shares biggest intraday gain in nearly 4 months
* Mining stocks down as BHP cuts 2019 copper output guidance
* NZ up for 2nd time in 13 sessions (Updates to close)
Oct 17 (Reuters) - Australian shares climbed on Wednesday, adding to gains from the previous session, as upbeat Wall Street earnings buoyed investor sentiment, with financial stocks the biggest drivers.
The S&P/ASX 200 index .AXJO closed 1.2 percent higher, its biggest one day gain since June, at 5,939.1. The benchmark added 0.6 percent on Tuesday.
U.S. stocks had jumped more than 2 percent overnight following upbeat earnings reports from major companies including UnitedHealth (NYSE:UNH) and Goldman Sachs (NYSE:GS). MKTS/GLOB
In Australia, financial stocks .AXFJ climbed 1.4 percent, supported by the country's banks, which were comfortably in positive territory.
National Australia Bank NAB.AX , the country's number four lender, on Tuesday joined its three major peers in refunding customers it had overcharged, to the tune of A$314 million ($224 million). All of the "big four" banks will report earnings in coming weeks. country's biggest banks have been in damage control mode after a powerful inquiry into the sector uncovered widespread misconduct. the rally, mining stocks largely traded lower as global miner BHP BHP.AX cut its fiscal 2019 guidance for copper production, citing outages at key mines. fell 0.7 percent, but its losses were capped as the miner also reported an 8 percent increase in first quarter iron ore production on strong Chinese demand, suggesting the trade tussle with the United States has not dampened demand by the world's second largest economy and Australia's largest export partner.
New Zealand's benchmark S&P/NZX 50 index .NZ50 rose 1.2 percent or 108.34 points to close at 8,911.79, marking only its second session of gains in 13.
Index heavyweight a2 Milk Company ATM.NZ surged 9.2 percent to its highest in more than one week, as it affirmed that its first quarter revenue guidance is in line with expectations, and anticipates further growth in China an Australia and New Zealand. diary prices, meanwhile, fell for the fifth time in a row at an auction, as supply remained robust.