Dubai Airports Engineering Projects (DAEP) is preparing to award the enabling works for the first phase of the expansion of Al-Maktoum International airport by the end of this year.

“The contract will be awarded imminently,” says a source close to the project.

The bidders are understood to include the local Al-Naboodah Contracting Company, the local Ghantoot Group, and the local Tristar.

The ambitious expansion programme planned for Al-Maktoum International will make it the biggest airport in the world by 2050 with the capacity to handle 255 million passengers a year. In early November, DAEP told contractors that it will start tendering contracts for building work at the airport in 2015.

The new infrastructure and buildings will include a new terminal building, six nodes or concourses connected to the terminal by people movers, and three runways. The terminal will also be connected to the new metro link that Dubai’s Roads & Transport Authority (RTA) is planning.

The estimated cost of building the first phase is AED120bn ($33bn), making it the largest airport construction scheme ever undertaken in the world. Once complete, it will take the airport’s capacity to 130 million passengers a year and make it capable of accommodating 100 A380 aircraft at any one time.

Once the first phase is complete, a second phase will start that will increase the capacity further to 255 million with five runways, another terminal building and more concourses. The entire development will cover an area of 56 square kilometres and it is due to be completed by the end of 2021.

The concept design for the new terminal has been completed by a team of Lebanon’s Dar al-Handasah and France’s ADPI.

The airport plans were endorsed by the emirate’s ruler, Sheikh Mohammed bin Rashid al-Maktoum, in October. The development aims provide the necessary facilities to accommodate passenger and cargo growth, and will also allow Emirates to relocate its intercontinental hub operations to the new airport by the mid-2020s.

Al-Maktoum International is needed to further develop Dubai’s status as a global aviation hub, as growth opportunities at Dubai International airport are becoming limited due to its location in the city. That airport is already one of the busiest in the world. In 2013, it handled 66.4 million passengers, making it the world’s second-busiest airport for international passenger traffic after London’s Heathrow airport.