Lululemon Anthletica Inc.'s $(LULU)$ board has authorized a $500 million increase in the remaining authorization of the company's stock repurchase program, from $141.2 million to $641.2 million. The repurchase authorization has no time limit and does not require the buyback of a minimum number of shares, the retailer said in a filing late Monday. Shares of Lululemon advanced 0.6% in the extended session Monday after ending the regular trading day down 2.2%.