US convenience store operator Casey's General Stores has posted a 13% rise in first-quarter net income due to increases in sales of prepared foods, groceries and petrol.

The Ankeny, Iowa-based company reported net income of $13.8m for the first quarter to 31 July, compared to $12.2m a year earlier.

First-quarter revenue increased 11% to $609.9m from $551.2m a year earlier.

Sales of grocery and other merchandise rose 3% to $187.9m, while sales of prepared foods increased 8.7% to $47.4m, reported Dow Jones News Service.