BEIJING — The Chinese president, Xi Jinping, appears prepared to defy the Communist Party’s established script for transferring power and delay the designation of his successor until after a party congress next year, unsettling the party elite and stirring speculation that he wants to prolong his tenure.

The delay would buy Mr. Xi more time to promote and test favored candidates and prevent his influence from ebbing away to a leader-in-waiting, experts and political insiders said. But the price could be years of friction while a pack of aspiring cadres vie for the top job, as well as unnerving uncertainty over whether Mr. Xi wants to stay in power beyond the usual two terms as party leader.

Although Mr. Xi’s decision will not be known until late 2017, the suggestion that he intends to break with precedent and begin his second term without a probable successor is magnifying uncertainties about who will rise and who will fall in the expected shake-up, including questions about the fate of the premier, Li Keqiang.

“It’s a very delicate issue,” said a member of the party establishment who regularly speaks with senior officials. He spoke on the condition of anonymity because of the party’s ban on discussing sensitive internal decisions.