The absolute majority won by separatists in a regional election on Thursday was a victory of the "Catalan republic" over the Spanish state, said secessionist leader Carles Puigdemont as the final vote count rolled in.

With 96 per cent of ballots counted in a vote to elect Catalonia's regional parliament, separatist parties are expected to win 70 seats out of 135, with Puigdemont's Together for Catalonia party retaining its position as the largest separatist force.

Puigdemont was speaking from Brussels, where he went into self-imposed exile after his government was sacked by Spanish Prime Minister Mariano Rajoy in October after it declared independence from Spain.

At pro-independence rallies around Barcelona, supporters chanted "President Puigdemont" and "Long Live the Catalan Republic" as the results came in, with some unfurling giant red-and-yellow pro-independence flags.

"I feel happy and relieved. We want independence now — no more waiting," said Elena Carreras, a 51-year-old teacher, smiling broadly as a band played the drums nearby.

The results surprised pollsters, who were expecting separatist parties to lose control of the parliament and face weeks of haggling over a viable coalition.

The pro-independence parties in Catalonia include Together for Catalonia — led by deposed president Carles Puigdemont — as well as Popular Unity Candidacy (CUP), and Republican Left of Catalonia (ERC).

If the results are confirmed following final vote counts, it will mean the three pro-independence parties again have a chance to form a regional government, nearly two months after Spain dismissed the previous government.

But it's still not clear if the three parties, who together pushed ahead with a banned independence referendum, can agree now to form a new government.

The unionist Citizens party, led by 36-year-old lawyer Ines Arrimadas, looks set to become the biggest single party, with 37 seats in the parliament. The leader of the pro-Spanish party that won the most votes in Catalonia's elections promises her party will continue to fight the region's separatists.

"The pro-secession forces can never again claim they speak for all for Catalonia," said Arrimadas late Thursday as the final results rolled in. "We are going to keep fighting for a peaceful co-existence, common sense and for a Catalonia for all Catalans."

If confirmed, the election result could open a new, uncertain chapter in Spain's political story and cast doubts over Spanish Prime Minister Mariano Rajoy's ability to draw a line under a crisis that has damaged Spain's economy and prompted a business exodus away from Catalonia.

The election has become a de facto referendum on how support for the separatist movement has fared since Rajoy sacked Catalonia's government for holding a banned referendum in October on splitting with Spain and unilaterally declaring independence.

Rajoy had hoped the election would return Catalonia to what he has called "normality" under a unionist government, or with a separatist government that will not seek a unilateral split.

Speaking to Catalan reporters in Brussels, Puigdemont said before vote counting began that "from the results will come the formula to recover democracy" in Catalonia.

Puigdemont fled to Belgium after central government authorities sacked him for pushing ahead with unilateral independence for the region. Other members of his former cabinet were jailed under preliminary sedition charges.

"It's not normal, an election that takes place with candidates in prison and candidates in exile," Puigdemont said, referring to his own situation as an imposed absence.

The separatist politician, who can't vote from Belgium, thanked in a tweet an 18 year-old woman who on Thursday cast a ballot paper on his behalf in a town near Barcelona.

Turnout on Thursday reached a record high, with over 83 per cent of eligible Catalans voting.

The atmosphere was one of peace and order as long queues of voters formed, in contrast to the Oct. 1 referendum, which was marked by police firing rubber bullets and wielding truncheons to prevent people voting as the central government cracked down on the illegal ballot.

The independence crisis has damaged Spain's economy and prompted a business exodus away from Catalonia, its wealthiest region, to other parts of the country. Direct foreign investment in Catalonia fell by 75 per cent in the third quarter from a year earlier, according to economy ministry data this week. More than 3,100 companies have moved their legal headquarters out of the region since the beginning of October.

The crisis has also caused concern in other European countries with secessionist regions.

Analysts said a new absolute majority for the pro-independence camp puts the ball back in the central government's court.

"What this shows is that the problem for Madrid remains and the secession movement is not going to go away," said Antonio Barroso, deputy director of research at London-based research firm Teneo Intelligence.