Chinese leader Xi Jinping is angry about a Hong Kong company’s plan to sell Panama Canal ports to a U.S.-led group, in part because the company didn’t seek Beijing’s approval in advance, people familiar with the matter said.

Chinese authorities have begun looking into CK Hutchison Holdings Ltd.’s sale of its overseas port businesses, people familiar with the matter said, amid signs that Beijing is unhappy that the Hong Kong conglomerate divested its Panama operations under US pressure.

China has sent a senior-level delegation to Panama at a time when relations have been clouded by developments surrounding the Panama Canal, a move seen by observers as an attempt to "understand what is unfolding" and possibly reverse the situation.