Consensus has been reached on the financing for a bridge linking Hong Kong and Macao, China's two special administrative regions, and Zhuhai, a special economic zone in Guangdong, a senior official from the province said on Friday.

Li Miaojuan, director of the Guangdong provincial reform and development commission said consensus had been reached between the mainland and the two regions.

The three sides have agreed to share the cost of the construction based on the principle of cost-to-benefit ratios, which takes into account the economic benefits to each side, Li said.

Hong Kong will contribute 50.2 percent, the mainland 35.1 percent and Macao 14.7 percent, the sides agreed.

The main span of the bridge will stretch 29.6 km from an artificial island off Gongbei to the west, to an artificial island, built for the tunnel section, to the east. It will carry a six-lane expressway on which the speed limit will be 100 kph.

To ensure unimpeded sea traffic in the main channels around the ports of Guangzhou and Shenzhen, a tunnel will be built linking the two islands.

In another development, Hong Kong Financial Secretary John Tsang Chun-wah on Wednesday said an engineering and environmental feasibility study for a third runway at Hong Kong International Airport will be carried out this year.

He said the additional facility, which is estimated to cost about HK$70 billion ($9 billion) will provide a boost to tourism in the region.