The Dow Jones industrial average fell while the S&P 500 and Nasdaq indexes were little changed on Wednesday following two days of strong gains, as the first wave of quarterly earnings reports trickled into the market.

The third-quarter earnings season begins in earnest after the market close when Alcoa Inc releases its results.

Investors have eagerly anticipated corporate earnings, searching for signs the developing economic recovery is translating into improved corporate profits and top-line growth.

The market has given earnings the benefit of the doubt and moved up in anticipation of continued improvement, said Keith Hembre, chief economist at First American Funds in Minneapolis. Expectations have become quite robust lately.

Retailers Costco Wholesale Corp , up 2.2 percent, and Family Dollar Stores Inc , 1.5 percent higher, rallied after they posted profits that topped expectations.

Monsanto Co fell 1.4 percent after it reported a fourth-quarter loss that widened from the prior year.

The Dow <.DJI> lost 25.17 points, or 0.26 percent, to 9,706.23. The Standard & Poor's 500 Index <.SPX> lost 0.21 points, or 0.02 percent, to 1,054.51. The Nasdaq Composite Index <.IXIC> was up 2.89 points, or 0.14 percent, at 2,106.48.

Google Inc , up 2.1 percent to $509.15, boosted the Nasdaq after the company's chief executive said the worst of the advertising recession was over.

Alcoa traded up 0.6 percent at $13.97 ahead of its results.

There's a little bit of wait-and-see with Alcoa. Those results are going to set the tone for the market for the next couple of days, said John Praveen, chief investment strategist at Prudential International Investment Advisors in Newark, New Jersey.

Verisk Analytics Inc surged 24 percent to $27.17 in its trading debut on Wednesday, a day after it raised $1.88 billion in the biggest initial public offering by a U.S. company since March 2008.

Energy stocks lost early gains, and crude oil futures turned sharply negative after a government report showed gasoline supplies rose more than expected last week.

November crude futures dropped 2.4 percent to $69.15 per barrel. The S&P Energy index <.GSPE> was off 0.8 percent.

(Editing by Padraic Cassidy)