BEIJING - Alibaba changed its leader on Friday in what the company describes as "a year of transition" for the world's largest online retail giant.

Jack Ma, 48, stepped down as Alibaba CEO, with 43-year-old Jonathan Lu Zhaoxi taking over the reins at its headquarters in Hangzhou, eastern China's Zhejiang province.

Keeping his position as board chairman, Ma said that he was "no longer young" enough for the Internet industry in his letter of resignation.

According to his own plan, 2013 is the "year of transition" for Alibaba with three major developments - platform, finance and data.

With an initial public offering potentially on the cards, Alibaba faces three challenges - management, listing and innovation, according to industry insiders.

Challenges post-Ma

The news that Ma was to step down now was disclosed at the 10th anniversary celebration of Taobao.com, the country's largest online shopping site, with 24 million transactions per day.

It was expected sooner or later as Ma first announced his decision to step down on Jan 15. Alibaba chose Ma's successor in March.

Lu, Alibaba executive vice president, has been at the group since 2000, founding the Alibaba.com sales team and its online payment service, Alipay.

"Lu is definitely facing multiple specific challenges as a new leader of such a massive industry giant, which is large in size and extensive in its domains," said Alamusi, the associate director of the Policy and Law Committee of China Electronic Commerce Association.