Many nations in the region are racing to invest in their roads, rail and energy systems to raise their competitiveness, following decades of under investment in the sectors.

Jean-Philippe Prosper, East and Southern Africa Director at International Finance Corporation (IFC) said they raised investment in the region this year from $2.2 billion in 2011, with projection it may hit about $4 billion next year.

"This year, we will invest probably $3.2-3.5 billion. It will be disbursed progressively. We will do projects in about 30 countries in Sub-Saharan Africa," Prosper said.

The corporation would for the first time ever invest more than $1 billion in infrastructure on the continent in one year.

In east Africa's biggest economy, Kenya, Prosper said IFC planned to invest up to $600 million, with four projects, including the Kenya-Uganda railway as well as three energy projects.

Another $100 million would be disbursed to Kenya's Equity bank in the form of a loan to expand lending to small and medium enterprises (SMEs).

SMEs face greater business obstacles than large enterprises in securing loans, Prosper said.

(This story corrects IFC's 2011 investment in Africa to $2.2 billion not $2.7 million)

(Reporting by Beatrice Gachenge; Editing by Duncan Miriri, Ron Askew)