Andrew Mason, founder of online deal site Groupon Inc. and a Mt. Lebanon native, was fired on Thursday by the struggling company because it reported a bigger-than-expected loss and a weak revenue outlook. Mason rejected a $6 billion merger offer from Google in 2010 before taking his company public in 2011 for $20 a share, which valued the company at $13 billion. Mason was said to have fretted that a sale to Google would sap employee morale and alienate business clients. Groupon's stock has lost about 77 percent of its value since the IPO, losing $1.45, or 24 percent, on Thursday to close at $4.53. The stock, which soared as high as $31.14 in its debut on Nov. 4, 2011, gained 4 percent in after-hours trading upon news of Mason's firing. Mason's ouster was anticipated for months and happened amid worries that people are tiring of the myriad daily online restaurant, spa and Botox deals that Groupon built its business on. Mason sent a memo to employees after he was fired.