Campbell Soup Co. reported a 16 percent drop in fiscal first quarter net income, citing the company's increased investment in marketing to boost soup and snack sales.

For the first fiscal quarter ended Oct. 28, the world's biggest soup maker earned $171 million, or 42 cents per share, compared to $204 million, or 47 cents per share, a year earlier.

Excluding special charges for restructuring its manufacturing plants in Australia, Campbell earned $174 million.

Per-share earnings were a penny more than the consensus forecast of analysts surveyed by Thomson Financial/First Call.

Sales for the quarter climbed 9 percent to $1.73 billion, up from $1.58 billion a year earlier, thanks to stronger than expected sales of soup and sauce products.

Last month, the company reported that its first-quarter earnings would be higher than originally forecast because of a significant increase in product shipments since the Sept. 11 terrorist attacks. It raised its earnings estimate for the first quarter to a range of 40 cents to 42 cents per share from 33 to 36 cents.

While chief executive Douglas R. Conant said Campbell is pleased with the effect its marketing investments have had on sales, he warned the events on Sept. 11 created unusual circumstances in the first quarter.

"While the year has started strong and we are well positioned moving into the heart of the U.S. soup season, it is difficult to determine how shipments will trend going forward,'' Conant said.

Besides its flagship soups, Campbell makes Pepperidge Farm snacks, V8 beverages, Prego and Franco-American pasta and sauces, and Godiva chocolates.