Yahoo to Keep Alibaba Stake but Spin Off Core Businesses

SAN FRANCISCO — Even after the Internal Revenue Service refused in September to grant its blessing to Yahoo’s proposed tax-free spinoff of its $32 billion stake in the Chinese e-commerce giant Alibaba, Marissa Mayerwas determined to go forward with the deal. In late October, Ms. Mayer, Yahoo’s chief executive, told shareholders that the plan was on track, and the preparations were still continuing last month.