Nigeria's main share index rises to 18-week high after presidential polls

A board showing stocks displayed on the wall at the Nigerian Stock Exchange in Lagos, February 13, 2015. REUTERS/Joe Penney

LAGOS (Reuters) - Nigeria's main stock index surged almost 3 percent to an 18-week high on Thursday, with investors snapping up shares after a peaceful presidential election in Africa's biggest economy won by opposition leader Muhammadu Buhari. The index which has risen for 10 straight sessions, has erased all its losses so far this year, as relief that the elections avoided the violence of previous polls.