Los Angeles Overstock.com Inc. said on Wednesday that co-founder Jason Lindsey resigned his positions as COO, president and board member of the online retailer, effective December 31, 2007.

Lindsey, who came out of retirement in April 2006 to help rebuild the company, will oversee special projects at Overstock on a part-time basis, the company said in a statement. Lindsey also said he would spend time on "outside ventures."

He is the third board member to resign from Overstock in 2007.