Kenya has invited bids for the design and construction of three berths at its second port at Lamu on the northern coast, the head of the Kenya Ports Authority (KPA) said on Monday.The $5.3 billion port is part of a $23 billion transport corridor project to link Lamu to Ethiopia and newly independent South Sudan, bringing investment and much-needed jobs to the region.It also includes the construction of a railway, pipeline, highway, airport and refinery.Gichiri Ndua, managing director of KPA, said the request for expressions of interest was open to local and international firms.As well as cutting over-reliance on Kenya’s existing Mombasa port, the project is aimed at deepening trade in east Africa and opening up northern Kenya, a vast area whose economy lags behind the rest of the country.