Clorox Co posted disappointing quarterly results and narrowed its full-year outlook on Tuesday, hurt by rising packaging costs, and the consumer products maker's shares fell 3 percent premarket.

To alleviate pressure on its margins, the company said it raised prices on its Glad trash bags by 9.5 percent, effective May 2.

The company, which also makes Hidden Valley Ranch salad dressing and its namesake bleach, is hopeful that new products like Brita water bottles, price increases and the appetite of affluent shoppers can help it rebound after a disappointing first half of the fiscal year.

Net earnings were $151 million, or $1.09 per share, in the fiscal third quarter that ended in March, compared with a profit of $165 million, or $1.16 a share, a year earlier.

Excluding items, the company earned $1.02 a share. Analysts on average were expecting $1.04 per share, according to Thomson Reuters I/B/E/S.

Sales rose 1.3 percent to $1.30 billion, while analysts had expected $1.32 billion, according to Thomson Reuters I/B/E/S.

Clorox said it now expects 2011 earnings of $3.85 to $3.95 per share. Its prior forecast called for $3.85 to $4 per share. It said sales should be flat to down 1 percent, as the weak economy continues to hurt sales in its categories. It also said it now expects its gross margin to decline by 75 to 100 basis points, due to higher commodity costs.

For fiscal 2012, the company said it expects earnings of $4 to $4.10 per share, including investments worth 18 cents to 20 cents per share. It expects sales to grow 1 percent to 3 percent, and its gross margin to shrink by 25 to 50 basis points.

Analysts on average were expecting earnings of $3.94 per share for 2011 and $4.40 per share for 2012.

Clorox shares fell 3 percent to $67.90 in premarket trade, from their close on Monday at $69.99 on the New York Stock Exchange.

(Reporting by Martinne Geller in New York and Brad Dorfman and Jessica Wohl in Chicago, editing by Dave Zimmerman)