CAMDEN, N.J. — As the result of first-quarter results that fell short of expectations, the Campbell Soup Co. is lowering its full-year guidance and outlook for the remainder of the year.

Increased promotional spending, weak economic conditions and strong competitive pricing activity were to blame for first-quarter results that are estimated to show a decline in net sales of 1%.

“Our increased promotional spending in the first quarter behind U.S. soup did not produce the planned volume gains,” said Douglas R. Conant, president and chief executive officer. “This result was due in part to even deeper soup promotions by competitors, which we chose not to match. While economic conditions remain challenging and competition intense, especially in U.S. soup, many of our businesses continue to perform well. Over the balance of the year we believe that revised promotional strategies and continued cost and expense initiatives will yield stronger results, especially in the second half of the year.”

The company now expects net sales growth of 1% to 3%, EBIT comparable to the previous year and e.p.s. growth of 2% to 4% from the fiscal 2010 adjusted base of $2.47.