Alibaba Group Holdings Ltd., China's biggest e-commerce company, has begun preparing for an initial public offering in the U.S. this year and has hired Morgan Stanley (CREDMS) and Credit Suisse Group AG (CS) as underwriters, China Internet platform Sina reported on its website, citing investment banking sources.

The company has said it is weighing a filing either in the U.S. or Hong Kong. Alibaba told Sina it hasn't yet decided on a location for the IPO filing and underwriters had not been selected.