(Adds ASX investigation, new quote)
SYDNEY Oct 18 Australia's stock market
regulator and the exchange operator ASX said they would look
into a spike in the price of some major stocks in the benchmark
S&P/ASX 200 index at the start of trading on Thursday.
Stocks including Australia and New Zealand Banking Group
(ANZ), gaming group Aristocrat Leisure, AGL
Energy and pallets distributor Brambles jumped
as much as 7 percent when the market opened at 10 a.m. local
time (2300 GMT).
The Australian Securities and Investments Commission (ASIC)
said in an emailed statement it had "commenced enquiries with
the market participants involved in trading in these stocks and
"This is not a formal investigation," it added.
The ASX said it observed some "unusual trading" in the first
"AB" group of stocks when markets opened and said it would
examine what happened. The ASX opens trade in alphabetical
"Clearly what happened was not usual and ASX will closely
examine to find an explanation," ASX spokeswoman Matthew Gibbs
said in a statement.
The ASX noted that Thursday was the expiry day for the
October ASX 200 Index futures contracts, which often generates
heightened activity as investors seek to unwind their positions.
The ASX said the affected stocks opened higher, but
retreated to lower levels immediately after opening. It said
trade throughout the rest of the day was orderly and the bourse
was ready to assist the regulator if necessary.
Shares in ANZ soared 6.4 percent to A$27.63 at the open in
heavy volume, before closing virtually flat. If sustained, the
move would have been its biggest one-day climb since early 2009,
during the global financial crisis.
(Reporting by Jane Wardell; Editing by Sanjeev Miglani)