US STOCKS-Wall St slightly extends gains, lifted by deals

* Merck (Other OTC: MKGAF - news) to buy Idenix; Analog to purchase Hittite

* Apple (NasdaqGS: AAPL - news) sees heavy trading following stock split

* 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 mid-afternoon, changes byline)

By Caroline Valetkevitch

NEW YORK (Frankfurt: HX6.F - news) , June 9 (Reuters) - U.S. stocks edged higher on Monday, pushing the Dow and S&P 500 to intraday record highs again after a series of deals, though Wall Street's fear gauge also bounced back.

If the S&P 500 ends higher on Monday, that will mark its 11th rise of the past 13 sessions, and its seventh record close of the past eight trading days.

The CBOE Volatility index rose 5.8 percent to 11.35 following its drop on Friday to its lowest level since February 2007. 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.

A flurry of merger activity gave investors a reason to buy some stocks on Monday. Merck (Dusseldorf: 6MK.DU - news) & Co said it has agreed to buy Idenix Pharmaceuticals Inc (NasdaqGS: IDIX - news) in a deal valued at about $3.85 billion. Analog Devices Inc (NasdaqGS: ADI - news) said it would buy Hittite Microwave Corp in a deal valued at $2 billion.

Tyson Foods Inc (NYSE: TSN - news) prevailed over Pilgrim's Pride Corp in a bidding war over Hillshire Brands Co, offering to buy the maker of Jimmy Dean sausages for $8.55 billion, including debt.

Shares of Idenix more than tripled, surging 231.4 percent to $23.96 on heavy volume, while Hittite shot up 28.7 percent to $77.92. Hillshire rose 5.2 percent to $61.98. Merck, a Dow component, was flat at $57.85. Analog gained 5.1 percent to $55.40. Tyson (Taiwan OTC: 4134.TWO - news) slid 5.2 percent to $38.03.

The Dow Jones industrial average rose 10.61 points or 0.06 percent, to 16,934.89. The S&P 500 gained 1.31 points or 0.07 percent, to 1,950.75. The Nasdaq Composite added 11.96 points or 0.28 percent, to 4,333.36.

Earlier, the Dow set an intraday record high at 16,970.17, while the S&P 500 touched an all-time intraday high at 1,955.55.

Apple Inc was the Nasdaq's most active name, rising 1.6 percent to $93.73 in heavy volume in the tech titan's first trading session after a seven-for-one stock split.

On Friday, the Nikkei news service reported that Apple was preparing to sell its first wearable device in October, aiming to produce 3 million to 5 million smartwatches a month in its initial run.

Family Dollar Stores Inc (NYSE: FDO - news) jumped 13.6 percent to $68.75 as the S&P 500's biggest percentage gainer after hedge fund billionaire Carl Icahn disclosed late on Friday a 9.39 percent stake in the company, making him the discount retailer's largest shareholder. Dollar General Corp climbed 9 percent to $63.23.

(Additional reporting by Ryan Vlastelica; Editing by Jan Paschal)