US packaged foods maker ConAgra Foods has posted lower first-quarter earnings, due to higher costs and the sale of some of its commodity businesses.

The company reported net income of US$135m, or 26 cents per share, for the first quarter to 29 August, compared to $195m, or 37 cents per share, in the year-ago period.

Sales increased 8% to $3.5bn from $3.2bn last year. Operating profit was $341m, 9% above the $312m reported last year.

"Our first quarter sales were very strong, reflecting excellent volumes for many of our brands. Our sales and marketing initiatives are gaining significant momentum, and we are pleased with the progress," said chairman and chief executive officer Bruce Rohde.

"And because we have taken some price increases and reduced operating expenses in several areas, our overall operating profit this quarter was solid, but it was not as strong as we wanted; this was mainly due to significantly increased input costs across the industry. As we plan for the balance of this fiscal year, we expect to continue making price adjustments to offset increased input costs, as well as to continue growing volumes and capitalising on cost savings opportunities so that we strengthen margins throughout the year," Rohde added.