China has called on its biggest state firms to take a more active role in Hong Kong, including stepping up investment and asserting more control over companies in the financial hub, executives familiar with the matter said as Beijing attempts to calm months of unrest in the city.

At a meeting this week in Shenzhen, bordering Hong Kong, senior representatives from nearly 100 of China's largest state-run companies were urged to do their part to help cool China's biggest political crisis in years, said three executives, including one who was present.

At the meeting, the state-owned enterprises pledged to invest more in key Hong Kong industries, including real estate and tourism, in a bid to create jobs for local citizens and stabilize financial markets, two of the executives said, speaking on condition of anonymity to discuss internal deliberations.