China’s Didi Chuxing Technology Co. is holding discussions about a multibillion-dollar initial public offering as early as this year, a move that would vault the ride-hailing company into the public markets ahead of American rival Uber Technologies Inc., according to people familiar with the matter.

Didi—which operates China’s largest ride-sharing platform and is expanding in Latin America and other parts of Asia—is hoping to fetch a valuation of at least $70 billion to $80 billion if it goes public, one of the people added....