There’s a new executive in charge at specialty apparel retailer Urban Outfitters Inc.

Effective immediately Urban Outfitters, No. 48 in the Internet Retailer Top 500 Guide, is replacing Glen Senk as CEO with chairman Richard Hayne.

Urban Outfitters didn’t give a reason for the sudden departure of Senk, who the company says is leaving to pursue another opportunity. But the retailer’s financial house, including online, is in order.

Urban Outfitters has yet to release its financials for the first quarter of fiscal 2012. But the company says holiday sales for November and December increased about 11% to $577 million from about $520 million in the same months in the prior year. Direct sales, which are almost entirely online, grew 17% while comparable-store sales over the Christmas shopping season grew 4%.

Hayne, who co-founded Urban Outfitters in 1970, has been chairman and president of the company since 1976. Senk joined Urban Outfitters in 1994 as president of the Anthropologie brand and was named CEO in 2007.

In fiscal 2011 Senk’s compensation package from Urban Outfitters totaled about $2.5 million, including a base salary of just over $1 million. The retailer’s e-commerce brands include UrbanOutfitters.com, Anthropologie.com, Freepeople.com, BHLDN.com and ShopTerrain.com.