Kellogg Co. saw the amount of waste the company sent to landfills increase last year, reversing a years-long decline.

"There is no single reason for our increase in waste to landfill in 2011; some plants continued to achieve decreases, while others saw their numbers rise, sometimes due to unforeseen circumstances," the Battle Creek, Mich., food company said in its new corporate responsibility report.

For example, a company plant in Springs, South Africa, was forced to send all food waste to landfill following a change in local regulations. It took much of the year to find a new waste contractor with the required permits to divert the material, the company said...