SINGAPORE, March 4 (Reuters) - Asian stocks tanked on Wednesday, with investors dumping crowded positions in chipmakers on ​worries Mideast war will drive an oil shock that raises inflation and delays interest rate cuts.

Deep falls ‌in Seoul triggered a circuit breaker as the KOSPI shed more than 11%, with two-day losses at 17% and the heaviest since 2009 while the won currency slumped to a 17-year low.

Japan's Nikkei fell 4.3% and Taiwan stocks dropped 3.6% as investors race out ​of what has been one of the hottest bets of the last few months in semiconductor makers.

S&P ​500 futures eased 0.6% and European futures gave up an early bounce to fall just ⁠below flat.

"There are too many negatives to hold a bid," said Christopher Forbes, head of Asia and Middle East ​at CMC Markets.

Benchmark Brent crude oil futures were on the rise and up more than 13% for the week ​at $82.08 a barrel, though prices have come off highs since U.S. President Donald Trump ordered an insurance guarantee on Gulf shipping and said the navy may escort oil tankers through the Strait of Hormuz.

U.S. and Israeli forces have pounded Iran for four days and Iranian ​drones and missiles have struck Gulf oil refineries and also U.S. embassies in Saudi Arabia and Kuwait.

"It does look ​like conflict is going to go a little bit longer than what people thought initially. And there's been escalation, because the ‌war is ⁠now broadening out to include allies of the U.S.," said Damien Boey, portfolio strategist at Wilson Asset Management in Sydney.

"Oil infrastructure seems to be under attack ... so people are having to think about what is the duration of all of that."

Japan, South Korea and Taiwan are all energy importers and have also been equity markets that gained strongly ​recently, and are taking extra ​selling pressure as investors cash ⁠out of winning positions globally and hunker down.

Gold, another strong gainer this year, fell about 4.5% overnight while a rally in the Aussie dollar has hit a speed bump ​and it slid below 70 cents on Wednesday.

On Wall Street, indexes pared heavier losses ​overnight but ⁠the S&P 500 closed 0.8% lower on fear over potentially prolonged higher oil prices.

"The biggest issue that (investors) are trying to weigh gets back to the intertwining of inflation and interest rates," said Chuck Carlson, CEO at Horizon Investment Services in Hammond, ⁠Indiana.

"Are energy ​prices going to remain elevated for a longer period of time ​than people thought yesterday, and then does that pass through?"

The euro was pinned at $1.16 as investors expect Europe will be hit hard by higher ​energy costs. Benchmark European gas prices have jumped about 65% in two days.