Alibaba Group, the online business-to-business group set up in 1999 by former tour guide and now billionaire Ma, plans to buy back most of the 40 percent stake in it that Yahoo bought for around $1 billion in 2005.

Under the plans being discussed, Alibaba Group would use bank loans and cash plus an asset swap to buy back about a 25 percent stake, leaving Yahoo holding 15 percent, the sources said. The U.S. group's 40 percent holding is worth an estimated $13-$14 billion, based on recent deal valuations.

Alibaba Group, one of the three leading players in the world's biggest Internet market, plans to pay a third of the consideration through a stake in one of its operating assets - making a deal tax-free for Yahoo - and the rest, around $6 billion, in cash, the sources said. It is looking to raise a loan of about $3 billion to help fund the deal.

The sources said taking Alibaba.com private was just one of the proposals being discussed, and was not a pre-condition of any Yahoo deal. Any final agreement could be several weeks away, they added.

Alibaba Group's plans are part of an overall deal being discussed by Yahoo, the Internet pioneer which is under pressure from its investors to turn around a lackluster performance. Last month, Yahoo appointed Scott Thompson as CEO to replace Carol Bartz who was fired in September, and co-founder Jerry Yang quit the company.

Yahoo shareholders are frustrated at stakeholders' apparent indecision over how to handle investments in Alibaba and other Asian assets.

"Alibaba.com's share price has been quite bumpy since its listing. Probably taking it private will make it more flexible for the group to do the transformation that it's going through," said Wendy Huang, head of regional Internet and media research at RBS in Hong Kong.

Trading in Alibaba.com shares was halted on Thursday pending an announcement regarding its parent. Alibaba.com, which is around 73 percent-owned by Alibaba Group, has a market value of nearly $6 billion, making the remaining stake in it worth around $1.6 billion.

Alibaba.com is the most likely operating unit in which Yahoo may be offered a stake, one of the sources said. Both parties have an understanding on this arrangement, but have not signed any formal deal yet, the source added.

Other Alibaba Group assets that could be used in a swap deal with Yahoo could include Taobao.com, often dubbed "China's e-Bay," Taomall, Yahoo (China) and Alipay, an e-payment business, sources said, adding Yahoo would get to choose which assets it wants.

The sources declined to be identified as the discussions were private. An Alibaba Group spokesman declined to comment.

Sources previously told Reuters that under a "cash rich split" plan being discussed, Yahoo would effectively transfer most of its 40 percent Alibaba stake back to the Chinese company, and all of its more than one-third stake in Yahoo Japan to Softbank Corp in return for cash and assets.

Shares in Softbank jumped more than 4 percent to a 5-week high of 2,319 yen on Friday. Softbank has an indirect stake of 31-32 percent in Alibaba.com as it holds close to a third of Alibaba Group and owns 58 percent of Alibaba Japan.

Yahoo had also entertained separate proposals from private equity firms TPG and Silver Lake about minority investments in the company, but those offers fell short of Yahoo's expectations.

(Additional reporting by Stephen Aldred, Kazunori Takada, Saeed Azhar, Melanie Lee, Chyen Yee Lee and Alexei Oreskovic; Editing by Muralikumar Anantharaman and Ian Geoghegan)

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