Seiyu Ltd., an affiliate of U.S. retail giant Wal-Mart Stores Inc., reported Wednesday a group net loss of 2.88 billion yen in the first half.

Seiyu attributed the January-June results to lower than expected sales and booking a special loss of 7.44 billion yen in costs, mostly related to its voluntary retirement program.

Comparable data from a year earlier were unavailable as Seiyu changed its accounting period to run through the end of December, rather than the end of February, to bring its financial statements in line with Wal-Mart.

In its group earnings report, the retailer said its net loss per share was 4.61 yen, while pretax profit came to 515 million yen on sales of 527.38 billion yen.