Alibaba is expected to begin an eagerly awaited roadshow for what could be the largest ever initial public offering early in the week of September 8, and its shares could list as soon as September 18 or 19, according to a person familiar with the situation.

The marketing trip, when company executives and Wall Street bankers meet with prospective investors, will kick off in Asia and include stops in Europe and the US, the person said. The Chinese ecommerce company is expected to raise about $20bn when it lists on the New York Stock Exchange, rivalling the Agricultural Bank of China’s $22.1bn IPO from July 2010, currently the largest on record. A price range for the shares is typically given just ahead of the start of the roadshow.

Alibaba’s ability to make a transition to mobile has been a focus of analysts and investors as China’s tech groups square off for customers glued to smartphones. Last week, the company announced a surge in mobile revenues for the second quarter.