ABUJA, July 10 (Reuters) - Portugal's largest builder Mota-Engil has signed an 840 million-euro ($920.05 million) contract to supply and finance railway rolling stock in Nigeria, strengthening its order book in Africa, the company said on Monday.

The contract is part of a $2 billion rail construction project connecting Nigeria and neighbouring Niger in the north, Mota-Engil said in a statement.

"The contract reinforces the commitment of the Nigerian government to improve the regional connectivity and the economic development in the north of the country, and strengthens the capacity of Mota-Engil Group to support that development effort in this region of Africa," the company said.

A consortium led by Mota-Engil, and two Chinese ventures, were short-listed by Nigeria's Lagos state for a $2.5 billion bridge in November.

Nigeria's government, under former President Muhammadu Buhari, has sought to rebuild the impoverished north of the country, parts of which have been ravaged for the past decade by Islamist insurgents.

The project is part of a government plan to build rail networks across Nigeria to address the poor transport infrastructure that has stymied economic growth for decades.

Nigeria's ministry of transportation didn't immediately respond to request for comment.

($1 = 0.9131 euros) ($1 = 0.9130 euros) (Reporting by Elisha Bala-Gbogbo; Editing by Sharon Singleton)