NEW YORK (AFP) - Yahoo announced plans Tuesday for a tax-free spinoff of its stake in Chinese Internet giant Alibaba, splitting off the valuable holdings from its core operations.

The move aims to deliver more cash for shareholders than an outright sale of the stake, which could be hit with a hefty tax bill.

Yahoo said its board had authorised the move to split off its remaining holdings in Alibaba into a newly formed independent investment company called SpinCo, shares of which would be distributed to Yahoo shareholders.

Yahoo's current market value is US$45 billion (S$60 billion), of which US$40 billion is in Alibaba shares.

"We have actively engaged experts in tax-efficient structures over the past two years and have considered a variety of alternatives," Yahoo chief finance officer Ken Goldman said in a statement.

"We remain aligned with our shareholders and our plan is designed to achieve the most advantageous return of capital to Yahoo shareholders with the absolute highest probability of success."

Yahoo will continue to operate its core business and hold its 35.5 per cent stake in Yahoo Japan.

Yahoo said separately its profit in the fourth quarter fell 52 per cent from a year ago to US$166 million while revenue was essentially flat at US$1.25 billion.

"I'm pleased to report that our performance in the fourth quarter and in 2014 continues to show stability in our core business," said chief executive Marissa Mayer.

"Our mobile strategy and focus has transformed Yahoo and yielded significant results."