Starbucks Corp. (SBUX) Wednesday said sales at company-operated coffee shops open at least 13 months rose a less-than-expected 7 percent in January, sending the company's stock down 3.8 percent.

Three Wall Street analysts' had forecast increases of between 8 percent and 10 percent, according to research notes. Starbucks itself has a long-term goal of posting monthly same-store sales increases of 3 to 7 percent.

The results marked the lowest monthly increase since Starbucks raised prices on its beverages by 6 percent last October. Last January, same-store sales rose 12 percent.

Early in the month, Starbucks introduced a new chocolate drink, called Chantico (search), aimed at reeling in customers outside the busy morning hours.

Starbucks Chief Financial Officer Michael Casey told Reuters last week that sales of the indulgent drink were meeting the company's expectations.

Starbucks shares fell $51.90 in after-hours trading on the Inet electronic brokerage following the announcement, from a Nasdaq close of $54.

Starbucks has nearly 9,000 coffee shops worldwide, about 5,400 of which are operated by the company.

The company's total sales rose 23 percent to $452 million during the four week period ended Jan. 30.