US STOCKS-Dow, S&P 500 extend string of record closes; VIX up
* Merck to buy Idenix; Analog to purchase Hittite
* Apple attracts heavy trading following stock split
* International Game Technology shares fly after Reuters report
* CBOE Volatility Index up, day after hitting lowest since Feb '07
* Dow up 0.1 pct; S&P 500 up 0.1 pct; Nasdaq up 0.3 pct (Updates to close)
By Caroline Valetkevitch
NEW YORK, June 9 (Reuters) - The Dow and S&P 500 ended at record highs again on Monday as more deal news raised enthusiasm for stocks, though Wall Street's fear gauge advanced.
It was a fourth straight record closing high for the S&P 500 and a third for the Dow. The gains, though, have been moderate in most recent sessions and volume lighter than average.
The CBOE Volatility Index rebounded after falling on Friday to its lowest level since February 2007. Wall Street's "fear gauge" rose 3.9 percent to end at 11.15. The VIX remains at nearly half of its historical average, which some analysts worry is a signal that the market is not fully accounting for issues that could derail the rally. Continuación...