Alibaba IPO ranks as world's biggest after additional shares sold

Alibaba's initial public offering now ranks as the world's biggest at $25 billion, netting underwriters of the sale a more than $300 million windfall after the e-commerce giant and some shareholders parted with additional shares.

The fees are equivalent to 1.2 percent of the total deal, with Alibaba paying $121.8 million in commissions. Selling shareholders are set to pay another $178.6 million, according to a filing with the U.S. Securities and Exchange Commission on Monday.

According to its prospectus, Alibaba had agreed to sell 26.1 million additional shares under the option, and Yahoo Inc an additional 18.3 million, netting the two companies an extra $1.8 billion and $1.2 billion respectively.

Alibaba's Jack Ma had agreed under the same option to sell an extra 2.7 million shares and company co-founder Joe Tsai agreed to 902,782 additional shares.

The source declined to be identified as the details of the additional sale have yet to be made official.

Alibaba declined to comment.

Citigroup Inc, Credit Suisse Group AG, Deutsche Bank, Goldman Sachs Group Inc, JPMorgan Chase & Co and Morgan Stanley acted as joint bookrunners of the IPO.