Shares are up 1.6% in after-market trading following the announcement. Yahoo disclosed the additional repurchase authorization as part of a larger finance plan that includes the raising of $1B in debt. The company says that it will privately sell senior notes — convertible into cash, common stock, or a combination — due 2018. Up to $200M could be used to repurchase the buyers’ stock. The rest will be used for “general corporate purposes, including, but not limited to, acquisitions or other strategic transactions, additional repurchases of common stock and working capital.” The company told investors last month that it spent $5.3B on stock repurchases since the beginning of 2012. Yahoo shares have appreciated 94% over the last 12 months, but some investors are growing impatient for proof that CEO Marissa Mayer’s efforts to upgrade services and buy properties including Tumblr will pay off. “While we believe it is unrealistic to expect a clear turn around in one year given where the business was, our view is that Yahoo’s core business is not where it should be to give us confidence that a turn-around is (highly) likely,” Bernstein Research’s Carlos Kirjner said last month after the company reported mixed results in Q3.