Overstock.com Inc. shares declined in the extended session Tuesday after the online retailer said it was launching a secondary offering of its stock. Overstock shares, which fell as much as 4%, were last down 1.5% after hours, following a 3.8% decline to close the regular session at $92. The company said it was offering 1.7 million shares, with an option for an additional 255,000 to underwriters Piper Sandler, Needham & Co., D.A. Davidson & Co. and Wedbush Securities. Overstock said it plans to use proceeds for general corporate purposes. Overstock already has about 40.3 million shares outstanding.Market Pulse Stories are Rapid-fire, short news bursts on stocks and markets as they move. Visit MarketWatch.com for more information on this news.