US food distributor Performance Food Group has reported lower quarterly earnings despite an increase in sales.

The company posted net earnings of US$18.8m, or 39 cents per share, for the second quarter to 3 July, compared to $23.9m, or 49 cents per share, in the year-ago quarter. The company said the earnings decline was a result of "previously disclosed operational challenges", such as higher costs.

Net sales rose to $1.6bn, an increase of 14% from $1.4bn in the year-earlier period.

Performance Food markets and distributes more than 64,000 national and private label food and food-related products to foodservice outlets.