US STOCKS-Wall St has worst day in four years, S&P now in correction
* All three major U.S. indexes tumble, now confirmed in correction
* Soon after the open, Dow was down more than 1,000 points
* Apple mostly recovers after falling as much as 13 percent
* Indexes close down: S&P 3.94 pct, Nasdaq 3.82 pct, Dow 3.58 pct (Adds bullet point, detail on market history, Asia futures)
By Noel Randewich
Aug 24 (Reuters) - U.S. stock indexes plunged almost 4 percent on Monday as investors, rattled about China's economy, sold heavily in an unusually volatile session that confirmed the S&P 500 was formally in a correction.
The Dow Jones industrial average briefly slumped more than 1,000 points, its most dramatic intraday trading range ever, with key component Apple falling heavily only to claw back and end down 2.5 percent.
It was the S&P 500's worst day since 2011 and followed an 8.5 percent slump in Chinese markets, which sparked a sell-off in global stocks along with oil and other commodities .
Wall Street had stayed in a narrow range for much of 2015, but volatility jumped this month as investors became increasingly concerned about a potential stumble in China's economy and after Beijing surprisingly devalued its currency, the yuan. Continuación...