* Miners drop as iron ore prices fall below $100/tonne
* Some companies with US exposure gain on the back of weaker Aussie
* Treasury Wine jumps after rejecting takeover offer (Adds analysis, quotes, stocks on the move)
By Thuy Ong and Naomi Tajitsu
SYDNEY/WELLINGTON, May 20 (Reuters) - Australian shares slipped 0.4 percent on Tuesday as sliding iron ore prices weighed on the big miners, but broader losses were offset by the weaker Aussie dollar lifting companies with large offshore earnings.
Miners continued to be sold off as spot iron ore prices fell to a 2-1/2 year low below $100/tonne, while China and Singapore futures hit record lows, under pressure from rising supply and weaker Chinese steel markets.
Index heavyweights BHP Billiton Ltd and Rio Tinto Ltd lost 0.6 percent and 0.7 percent, while Iluka Resources Ltd was down 0.6 percent.
Elsewhere, Australia's Treasury Wine Estates rocketed nearly 20 percent to mid-January highs of A$4.85 after saying it has rejected a A$3.1 billion takeoever offer from private equity giant Kohlberg Kravis Roberts & Co LP because the bid was too low.
The S&P/ASX 200 index slipped 13.4 points to 5,395.6 by 0200 GMT. The benchmark fell 1.3 percent on Monday, its biggest one-day percentage drop since mid-April.
"There's no doubt in the short term that downside pressure in markets will continue because global economic recovery in 2014 is softer and going to be more prolonged," said Matthew Sherwood, head of investment market research at Perpetual in Sydney, adding that investors were questioning the justification of cyclicly high market valuations.
"We're seeing investors sell out of lofty share market valuations, taking some profits and deploying capital in other parts of the market including the fixed-income market."
Companies with a large exposure in the U.S. market were boosted by a weaker Australian dollar as earnings are elevated when funds are repatriated.
Among these, QBE Insurance Ltd added 0.9 percent, while sleep apnea products manufacturer Resmed Ltd was up 0.3 percent.
The Aussie dollar is hovering close to 3-week lows of $0.9313.
Banks were choppy, falling after an initial rise, with Westpac Banking Corp down 0.7 percent, Australia and New Zealand Banking Group slipped 0.3 percent and National Australia Bank lost 0.8 percent. The three top-tier banks are currently hovering around two- to three-month lows.
Moko Social Media Ltd jumped 18.5 percent after the company announced it had filed for the company to be listed on the Nasdaq.
Genworth Mortgage Insurance Australia Ltd is set to debut on the domestic market at 0200 GMT, after raising A$583 million in Australia's biggest initial public offering this year. The issue price was A$2.65.
New Zealand's benchmark NZX 50 index slipped 0.3 percent to 5,149.51, as hefty losses in online auction site TradeMe weighed on the country's shares.
TradeMe fell more than 2 percent to NZ$3.53, its lowest in roughly two years, as investors dumped the stock on concerns that it was losing market share in the online real estate sales space.
"People are worried and disappointed that TradeMe wasn't able to hold onto its listings," Morningstar equities analyst Nachiket Moghe said.
"The growth outlook for the company is not as good as originally thought, they are also facing headwinds in their new goods auctions business," he said, adding that shares could fall further towards NZ$3.00 in the near term.
Editing by Eric Meijer