NEW YORK – Stocks closed mixed Monday as investors grew more cautious while they waited for the start of second-quarter earnings reports. They got some good news after trading ended, when Alcoa Inc. reported better than expected results.

The Dow Jones industrial average rose 18 points and the other big indexes also had slight gains. But almost two stocks fell for every one that rose on the New York Stock Exchange, a sign that investors were wary about earnings.

Alcoa beat analysts’ expectations, and said it was raising its forecast for consumption of aluminum this year. The company’s stock rose nearly 3 percent in after-hours trading.

Insurance broker Aon Corp. also said it will buy human resources company Hewitt Associates for $4.9 billion in cash and stock, and Playboy Enterprises Inc. founder Hugh Hefner offered to take the media company private. Avon Products Inc. agreed to buy Silpada Designs for $650 million in a bid to expand its jewelry business.

The Dow Jones industrial average rose 18.24, or 0.2 percent, to 10,216.27. The Standard & Poor’s 500 index rose 0.79, or 0.1 percent, to 1,078.75, while the Nasdaq composite index rose 1.91, or 0.1 percent, to 2,198.36.

Consolidated volume on the NYSE, which includes shares traded on other exchanges, came to a light 3.47 billion shares as many investors chose to sit out the day while they waited for Alcoa’s report.