Blackstone Group and Bain Capital are preparing a bid for all of Yahoo with Asian partners in a deal that could value the Internet company at about $25 billion.

The scheme includes China's Alibaba and Japan's Softbank and while it has not been finalised it will put pressure on Yahoo's lacklustre board to sell up. If the deal goes through it will value the outfit at more than $20 billion.

Alibaba wants to buying back the 40 percent stake owned by Yahoo has said that it is keeping its options open and said it has not decided whether to participate in a bid for all of Yahoo. Alibaba is , run by its founder and billionaire CEO Jack Ma, has ties with some of the world's most prominent private equity funds and a group of investors including Silver Lake which bought 5 percent of Yahoo in early November.

A bid for Yahoo at more than $20 per share would mean a deal value of about $25 billion based on 1.24 billion shares outstanding, potentially making it the largest leveraged buyout in recent years.