LAKELAND, Fla. — Publix reported a 13.4% increase in its fourth-quarter sales to $7.2 billion, the retailer said Thursday.

Net earnings for fourth quarter 2011 were $399.5 million, compared to $342.1 million in 2010, an increase of 16.8%. Comparable-store sales for the fourth quarter increased 5.3%.

Meanwhile, earnings per share were 51 cents, up from 44 cents per share in 2010.

For the 53-week year ended Dec. 31, Publix’s sales were $27 billion, a 7.3% increase from last year’s $25.1 billion, a 52-week year. The additional week in 2011 increased sales by 1.9%. Comparable-store sales for 2011 increased 4.1%.

“I’m pleased that our strong operating performance and improvements in the stock market resulted in an increase in our stock price,” Publix CEO Ed Crenshaw said. “Our associate owners deserve the credit for these results as they continue to make us a leader in customer service.”