Overstock.com Inc.'s board of directors has authorized an increase to the company's convertible senior notes repurchase program.

The online retailer said in a news release that the board authorized a $15 million increase to reduce Overstock.com's debt under its outstanding senior notes, which are due Dec. 1, 2011.

With the increase, the company now has $20 million authorized for repurchase.

Shares of Overstock fell 96 cents, or 6.2 percent, to $14.55 in afternoon trading Wednesday.