The governing Pe a Corsica (For Corsica) alliance — made up of the pro-autonomy Femu a Corsica (Let's Make Corsica) and pro-independence Corsica Libera (Free Corsica) — extended their vote share on Sunday to 56.5 percent, seeing off two center-right challengers as well as supporters of French President Emmanuel Macron in the second-round vote.
The alliance had already won 45.4 percent of the vote in last weekend's first round ballot. Turnout on Sunday was low, at 52.6 percent.
Sunday's outcome is expected to present a new challenge for Macron, who will have to decide whether to relinquish some control or maintain France's highly centralized government.
"Paris today has to take stock of what is happening in Corsica," said Gilles Simeoni (main photo), Pe a Corsica's leading candidate, after the results were announced.
Simeoni has previously complained that Macron has not been receptive to nationalist demands for greater autonomy and other claims. These include: recognition for special Corsican residency status to block property speculation fueled by foreign buyers of holiday homes, equal recognition for the Corsican language along with French and an amnesty for convicts they consider to be political prisoners. Some 30 militants remain in French prisons, according to Simeoni.
Read more: In Corsica, a language breeds controversy
'Corsica is not Catalonia'
The Corsican leader has stated independence from France is not a short-term aim.
Writing in Le Monde in November, Simeoni said "Corsica is not Catalonia," but said the region is seeking an agreement with Paris for autonomy within three years, to be brought into force within a decade.
Corsica accounts for less than 1 percent of France's GDP and receives substantial state subsidies. Agriculture and tourism are the main economic activities.
The newly elected assembly will start work early next year. Nationalists will also take 11 seats on the governing executive council, which carries out the same tasks as regional council presidents in mainland France.
The separatist militant group National Liberation Front of Corsica ended its 40-year bombing campaign against the French state in 2014. During the conflict, France's top official on the island, Claude Erignac was assassinated in 1998. Simeoni is the former lawyer for Yvan Colonna, who was convicted of Erignac's murder.
jm/cmk (AFP, EFE, dpa)