@GG, Winston & Guru its true as incredible as it seems. Remember centum (formerly ICDCI) is a scion of ICDC the parastatal which was affirmative action for indigenous investors. In 1970s minister of finance exempted the INVESTMENT INCOME (dividends) of icdci from tax. It so happens that over 90% of their income is from dividends and capital gains. Capital gains are also exempt from tax!

@sparkly, nobody is exempted from paying corp tax. You can pay at a reduced rate i.e. When you list on the NSE you are entitled to a reduced rate (I think 25% for 5 years).
Dividends are assessed at 5% with holding tax which is a final tax. Where Centum derives most of its income from dividends, it doesn't mean they are exempt from corp tax., its just that w/h tax is a Final Tax.
You can avoid w/h tax if you control 12.5% of the issued ordinary capital of a firm. If Centum have more than 12.5% of firms they have invested in, then they are exempt from w/h tax on dividends paid by those firms. Remember that w/h tax is withheld by the paying company, that doesn't mean Centum has not paid, it is that the paying firm is an agent for KRA and collecting at source, like your employer collects income tax by deducting from your pay and passing it on to KRA.