Yahoo Inc (YHOO.O) plans to spin off its 15 percent stake in China’s Alibaba Group Holding Ltd (BABA.N), responding to pressure to hand over to shareholders its prized e-commerce investment valued at roughly $40 billion. Shares of Yahoo rose about 7 percent to $51.45 in after-hours trading on Tuesday, following the tax-free spinoff announcement and earnings which just beat analysts forecasts even as its revenues slightly lagged estimates.