Chinese e-commerce giant Alibaba Group Holding Ltd is one of several companies that are in talks to invest for a stake in U.S.-based advertising technology firm AppNexus, the Wall Street Journal said, citing sources familiar with the matter.

The talks are in an advanced stage but there is no confirmation whether they would result in an investment, the Journal cited sources as saying.

Last week, technology publication The Information said Alibaba is looking to take stakes in several non-Chinese Web companies, citing an executive who was told about the company's recent U.S. plans.

AppNexus expects to raise about $100 million and is considering offers that value the company at more than $1 billion, the Journal reported.

Alibaba plans to gain competence in advertising through investment in AppNexus, while the latter looks to expand its reach outside the United States, Wall Street Journal reported the sources as saying.

Alibaba, which powers 80 percent of all online commerce in China, is gearing up for what could be the world's biggest technology initial public offering.

The company's listing has stirred the most excitement in Silicon Valley and Wall Street since Facebook Inc's record IPO.

A spokeswoman for AppNexus declined to comment. No one from Alibaba was available for comment after regular business hours.