* ASX sees benign, sideways day with profit taking - analyst
* Banks, mining stocks lose most
* Sigma Healthcare down over 5 pct, spurns takeover bid
* NZ dragged by financials, utilities
By Devika Syamnath
March 13 (Reuters) - Australian shares extended their losses on Wednesday, with banks and miners faltering as investors took some money off the table following a robust performance since the start of the year.
The S&P/ASX 200 index .AXJO softened 0.4 percent to 6,151.6 by 0104 GMT in "just a benign, sideways day with profit taking" according to James McGlew, executive director of corporate stockbroking at Argonaut.
"The Australian markets in the last couple of trading sessions has consolidated what has been a very steady rise from the beginning of the year."
The market, which reached its best close in six months on Thursday, has declined 1.4 percent since then. It had gained 9.4 percent so far this year.
Financial stocks .AXFJ led the day's losses, with three of the "Big Four" declining between 0.5 percent and 1 percent.
The sub-index had turned down late in Tuesday's session after the federal government said it would no longer seek to abolish hidden commission payments to home loan brokers by banks, reversing a key recommendation from an inquiry into the sector and potentially placing banks in the political spotlight. McGlew said Australia's big four are legislated to not fail and are "a protected species in Australia."
"The only thing out there at the moment that's a negative for the banks is the likelihood of a (opposition) Labour government getting in... on the well-documented news that their franking credits are going to be affected."
Recent shorting of second-tier Australian banks such as Bendigo and Adelaide Bank BEN.AX and Bank of Queensland BOQ.AX has added to investor concerns that higher regulatory costs will hurt smaller lenders more than the big four market leaders. stocks .AXMM were also under pressure, losing as much as 0.4 percent, with major global players Rio Tinto (LON:RIO) RIO.AX and BHP Group BHP.AX giving up as much as 0.9 percent, each.
Elsewhere, shares of pharmacy operator Sigma Healthcare SIG.AX fell as much as 5.7 percent after its board rejected a A$727 million ($513.48 million) takeover bid from Australian Pharmaceutical Industries API.AX . gold stocks .AXGD bucked the wider trend to gain as much as 1.8 percent on robust bullion prices. GOL/
New Zealand stocks .NZ50 declined, with financial and utility stocks driving the losses.
The benchmark S&P/NZX 50 index .NZ50 was 0.2 percent lower, or 17.89 points, at 9,379.36.
Energy retailer Mercury NZ MCY.NZ tumbled over 2 percent while NZ-listed shares of Westpac Banking Corp WBC.NZ lost as much as 1.9 percent. ($1 = 1.4158 Australian dollars)