The entity says his resignation was due to personal reasons. Dube was appointed as acting COO with effect from 1 April last year.
Sentech has not yet appointed a new COO, says PR and media manager Nthabeleng Mokitimi. She adds that the process is under way.
In the meantime, CEO Setumo Mohapi is carrying out the responsibilities of the COO, with the help of the senior management team.
At the time of Dube's resignation in July, Sentech had just appointed new CFO Protas Phili.
