MADRID — Catalonia’s main separatist parties took a significant step on Saturday toward ending the region’s political deadlock by voting on a presidential candidate who is not facing prosecution in Spain.

The candidate, Quim Torra, fell just short of winning a majority in Parliament, but he will get another chance in a second round of voting on Monday, when the threshold will be lower.

Mr. Torra, addressing lawmakers on Saturday, said he was committed to turning Catalonia into a republic even after the region’s failed independence effort in October. He also presented himself as a stand-in for Catalonia’s former leader, Carles Puigdemont, whom he called “our president.”

Mr. Puigdemont, who left the country to avoid prosecution, is awaiting a German court ruling on whether he should be extradited to Spain to stand trial on charges of rebellion related to leading Catalonia’s tumultuous independence drive. This past week, he endorsed Mr. Torra as his replacement after Spain’s Constitutional Court suspended a regional law that would have allowed him to be re-elected in absentia.