The Alibaba co-founder has penned a rare and lengthy memo to employees.

In it he expresses support for restructuring efforts at the e-commerce titan.

Some saw that as a signal he's ready to play an active role again after years out of the spotlight.

Ma largely disappeared from public view after making a speech critical of Beijing regulators in late 2020.

A massive share sale for financial firm Ant Group, which he also founded, subsequently got cancelled.

That was followed by a regulatory crackdown on the whole tech sector, with Alibaba fined $2.8 billion.

Ma has since spent much of his time abroad, including in Tokyo, where he is a visiting lecturer at a university institute.

Now the hint of a return comes after a turbulent year for Alibaba.

Twelve months ago it said it would split into six units, marking the biggest shakeup in its 25-year history.

It later announced, then cancelled, share sales for two of the divisions, and installed a new chief executive.

In his internal message, Ma praised company boss Eddie Wu, and the move to split into six.

He also said the firm needed to have the courage to admit and correct past mistakes.

Alibaba's Hong Kong shares surged around 5% on Wednesday amid investor hopes that Ma's comeback could now be in the offing.