* Metals and mining index slides nearly 3 pct
* Energy-share index hits an 8-month low
* Market struggling to price in uncertainty - analyst
By Niyati Shetty
Nov 21 (Reuters) - Australian shares plunged to a 15-month low on Wednesday with across-the-board losses, joining a rout in global equities as trade tensions and worry about global growth continued to shrink risk appetites.
At 0102 GMT, the S&P/ASX 200 index .AXJO was down 1 percent or 58.4 points to 5,613.4. The benchmark fell 0.4 percent on Tuesday.
"Our markets are quite adverse to risk at the moment and whilst markets can price in risk, it is very difficult to price in uncertainty," said James McGlew, executive director of corporate stockbroking at Argonaut.
The metals and mining index .AXMM fell as much as 2.9 percent as base metal prices slipped on worries of China-U.S trade tensions. MET/L
McGlew added that there is "a lot of uncertainty" in Asia-Pacific over the U.S.-China trade war, which at this stage "shows no signs of relenting".
Mining giant BHP BHP.AX declined 2.6 percent while peer Rio Tinto (LON:RIO) RIO.AX slumped 2.5 percent.
Energy stocks .AXEJ declined 3.2 percent and were at an eight-month low as oil prices tumbled. The sub-index fell for a fourth straight session.
Crude prices slumped more than 6 percent, caught in a broader U.S. equities sell-off on persisting worries about corporate earnings, slowing global economic momentum and trade tensions. MKTS/GLOB
Oil and gas explorers Woodside Petroleum and Santos Ltd fell 1.7 percent and 3.5 percent, respectively.
Conglomerate Wesfarmers Ltd WES.AX plummeted nearly 30 percent, reflecting the de-merger of its supermarket division Coles Group COL.AX , which commenced trading in the day. in the month, Wesfarmers shareholders approved the de-merger by which shareholders would receive one share in Coles for every share in Wesfarmers. shares .AXFJ also dropped, with lenders National Australia Bank NAB.AX and Macquarie Group MQG.AX declining 0.5 percent and 2.6 percent, respectively.
The sub-index for healthcare .AXHJ , usually a defensive sector, gained 1.3 percent. Index heavyweight CSL Ltd CSL.AX was up 1.9 percent.
New Zealand's benchmark S&P/NZX 50 index .NZ50 fell 0.74 percent or 64.39 points to 8,655.91.
a2 Milk ATM.NZ lost 4.5 percent and was the worst performer among kiwi shares, while Fletcher Building FBU.NZ was 3.9 percent down.
However, online marketplace operator Trade Me Group TME.NZ surged 20 percent on a NZ$2.54 billion ($1.72 billion) takeover offer by private equity player Apax Partners. ($1 = 1.4728 New Zealand dollars)