When did Nico Mak first sell WinZip to other party?

I know that Corel owns the WinZip but am not finding information about what time Nico Mak actually stop in the development of WinZip and someone else took it over.

I have done searching on Google but cannot find the answer. Could someone help?

Thank you

WinZip is owned by Corel. I have no idea who else is involved.

Originally the zip format came from Philip Katz, died sadly. The first Winzip came in 1991. Corel bought it in may 2006 from Mr Nico Mak, who then worked for Mansfield Software Group. They are almost out of business. Got almost nothing of the person Nico himself.