The Middle East's biggest sea port is growing.

Dubai port operator DP World said on Tuesday it is beginning a $1.6 billion expansion of the Gulf commercial hub's sprawling Jebel Ali port.

The expansion will add a fourth container terminal to the port on a reclaimed island north of one of its existing container terminals. The first phase of the project will be able to handle the equivalent of 3.1 million standard 20-foot shipping containers annually by 2018, boosting capacity by 16 percent.

Jebel Ali is the centerpiece of government-backed DP World's network of more than 65 marine terminals around the world.