The company running a high-speed Internet cable along Africa's east coast says it has reached a deal with Mozambique to provide a new link to landlocked Zimbabwe.

Under the agreement, the parastatal Telecomunicacoes de Mocambique (TDM) will allow its fibre-optic network to be used to link Zimbabweans to the 13,700-kilometre (8,500-mile) cable running along the coast, SEACOM said in a statement.

"This agreement with TDM demonstrates our commitment to partner with established players to improve the range of service to customers whilst continuously expanding the reach of SEACOM's low-cost services into land-locked countries across the region," chief executive Brian Herlihy said.

The deal, whose value was not released, will also give the company another route to link with regional powerhouse South Africa and landlocked Malawi, the statement added.

The undersea cable already connects to Zimbabwe through South Africa, but the extra route should improve the reliability of the service, it said.

New undersea cables along both sides of the continent have expanded the capacity of Africa's fibre optic cable connections almost 300-fold since 2009, when the continent relied mainly on excruciatingly slow satellite connections.