Challenges are forcing business firms to seek best management and marketing strategies so as to grow their market share and increase shareholder value. Companies in the Kenyan sugar industry must survive and satisfy their shareholders expectations in the industry in spite of low yields on the one hand and high costs of production and importation of low-cost sugar on the other.The market environment of the industry is complicated by regional integration by such bodies as Common Market for Eastern and Central Africa and East African Community.This research found out that in the year 2008 Mumias Sugar Company, the market leader with a share of 60 per cent, adopted diversification strategy to counter effects of Regional Trade Agreements which cause cheap sugar imports. The study revealed that the increase in market share, a rise in profit and revenue and a decrease in operational costs were highly related. In conclusion the study recommends that Kenyan sugar firms should lobby the Government to zero rate domestic sugar and they should diversify into other and value added as well as conduct research into production of fast-maturing cane.