The eight-year sharia-compliant loan was signed on 9 December and will be used to finance the development of the Haramain district within KAEC.
The city will house up to 2 million people in 250,000 apartments and 25,000 villas, creating 1.3 million jobs. It will include a seaport; an industrial area; an educational zone; a central business district with commercial, mixed-use and retail outlets and a financial island; and resorts; as well as a residential area.
Operations at the seaport, King Abdullah Port, began at the start of the year.
The loan from Alinma Bank follows the signing of a SR2bn ($553m) Islamic loan from Sabb in September, which will also be used to build residential and infrastructure projects in the city.
According to a 2012 masterplan, SR125bn will have to be spent on infrastructure development in the new economic city in the coming years.