Costco Wholesale Corporation reported net sales of $7.40 billion for the month of December, the five weeks ended Jan. 4, 2009, a decrease of two percent from $7.55 billion in the same five-week period last year.

For the first eighteen weeks of its reporting period ended Jan. 4, 2009, the company reported net sales of $24.92 billion, an increase of two percent from $24.53 billion during the similar period last year.

Total company comparable sales for the five-week period ended Jan. 4 decreased 2% and comp sales for the eighteen-week period increased one percent. Excluding the negative impacts from gasoline deflation and foreign exchange (primarily in CN, UK and Korea), total comp sales increased 2 percent and 3 percent for the five and eighteen-week periods, respectively.