HONG KONG — President Xi Jinping of China has used a meeting with some of Hong Kong’s leading industrialists to reinforce Beijing’s unyielding position against political change in the former British colony, lending his personal authority to the government’s efforts to undermine the pro-democracy movement here and to signal to the city’s business elite that it should toe the official line.

Details of the closed-door meeting, which took place Monday in Beijing with a group of Asia’s wealthiest men, emerged as attendees returned to Hong Kong in recent days. Four participants said in interviews that Mr. Xi stressed that any political change in Hong Kong must be in strict accordance with the existing legal code, called the Basic Law. In effect, Mr. Xi ruled out demands by pro-democracy supporters that would open up the nomination system for Hong Kong’s top position, the chief executive, they said.

China regained sovereignty over Hong Kong in 1997 in an agreement that guaranteed the territory would enjoy considerable freedom to run its own affairs for a half-century, and the ruling Communist Party has promised to allow Hong Kong citizens to vote for the territory’s top post in 2017. But last month Beijing set down rules that ensured that only candidates acceptable to the central government would be allowed to run for election. In response, an increasingly assertive pro-democracy movement here vowed to stage sit-in protests in Central, the city’s financial district.

The meeting with Hong Kong’s tycoons, who enjoy a combined net worth of tens of billions of dollars, took place the same day that thousands of students in Hong Kong gathered on a university campus to begin a weeklong boycott of classes to protest Beijing’s position. Many plan to take part in the mass sit-in, known as Occupy Central, which is expected to start next month.