The motion says Puigdemont — currently in self-imposed exile in Belgium — is the “legitimate” candidate for the regional presidency.
It also states that the separatists are “favourable to the constitution of Catalonia as an independent state”, but stops short of validating a failed declaration of independence on October 27th.
The short-lived breakaway attempt saw Spanish Prime Minister Mariano Rajoy sack the region's government, dissolve its parliament and call snap elections in December, in which separatist parties retained their absolute majority.
Since then, Catalonia has remained without a regional government and under direct rule from Madrid as divided separatist parties cannot agree who to pick as candidate for the presidency — their favoured contender Puigdemont being in self-exile in Brussels.
Puigdemont, who faces arrest at home over his role in the independence bid, wants to govern Catalonia remotely. But Spain's Constitutional Court has made his appointment conditional on his physical presence in the regional capital Barcelona.
Some separatist parties are now considering appointing someone else as presidential candidate and giving Puigdemont a “symbolic” role from Belgium.
According to Spanish media, Thursday's motion could be interpreted as a bid to pacify Puigdemont.
By recognising him as the “legitimate” candidate, there is hope he will step aside and let another separatist take his place in Catalonia, media say.
One of the possible contenders is Jordi Sanchez, the 53-year-old head of the ANC, a hugely influential pro-independence citizens' group.
But this too is problematic as he has been in prison for more than four months, charged with sedition over his role in the secession attempt.
On Thursday, opposition lawmakers pleaded with their separatist counterparts to come to an agreement.
“We need a government, a government that takes charge of problems and governs the 7.5 million Catalans,” said Miquel Iceta, the Socialist party's Catalan leader.
Xavier Domenech of the far-left Catalunya En Comu party said that Sanchez “had every right to be appointed president of Catalonia but we know that it's probably not the quickest shortcut to recover self-government.”