BEIJING - The Chinese government is mulling a regulation to curb irregular contracting in construction projects.

A draft regulation on the construction sector was put on the website of the Legislative Affairs Office of the State Council on Thursday to solicit public opinion.

The draft regulation bans one construction project from having more than one general contractor.

It also stipulates that only the general contractor can outsource the project to subcontractors. Subcontractors are banned from outsourcing again and the developer is banned from interfering.

Under the rules, the developer should not shorten the duration of a project unless the developer proves it is necessary, covers the extra costs and ensures that the construction quality will not be affected.

Malpractice in the contracting of construction projects has become a major cause of poor-quality housing and infrastructure projects in China. Some projects have been outsourced again and again among many contractors and subcontractors, making it difficult to check the qualifications of builders and supervise construction quality.

In a number of cases, irregular contracting has also resulted in defaulted payments to construction workers.

The draft regulation requires contractors to pay builders fully and promptly on a monthly basis.

Government-invested projects should not start construction without approval from the government planning department and until funds have been allocated.

In August, a ramp on a multi-million-dollar bridge in Harbin of northeast China's Heilongjiang province collapsed and four trucks plunged 30 meters to the ground, killing three and injuring five.

The bridge, which cost nearly $300 million and opened to traffic in November 2011, was planned to take three years to complete, but was completed in 18 months.

The collapse triggered public outcry over the safety of public facilities.