(Adds parliamentary election result, background)
BISSAU, April 16 (Reuters) - Guinea-Bissau's former finance minister, Jose Mario Vaz, will face Nuno Gomes Nabiam, an independent candidate, in a May 18 presidential run-off after no candidate secured a majority in the first round, the election commission said.
The presidential and parliamentary vote is meant to offer the country a fresh start after decades of instability since independence from Portugal. Its last vote in 2012 was abandoned after the military seized power between rounds of voting.
Vaz, candidate of the dominant party African Party for the Independence of Guinea and Cape Verde (PAIGC), secured 40.99 percent of the votes in the first round, according to election commission figures released on Wednesday.
Nabiam, the former chair of Bissau's civil aviation agency, came second with 25.14 percent, the figures showed. Nabiam comes from the Balanta ethnic group and is seen as having the support of the army.
The results showed that the PAIGC won a majority in the 100-seat parliament with 55 seats. The PRS, PAIGC's traditional rival, came second with 41 seats.
Weak state institutions, along with its array of islands and unpoliced mangrove creeks, have made the country a paradise for smugglers of Latin American cocaine destined for Europe. (Reporting by Bate Felix; Writing by David Lewis; Editing by Eric Walsh)