National Shipping Company of Saudi Arabia said on Sunday it had signed a murabaha facility with Riyad Bank valued at 1.425 billion riyals ($380 million) to finance the construction of five very large crude carriers. The facility lasts for 10 years and six months, and includes a maximum two-year grace period, the firm known as Bahri said in the bourse statement, Reuters reported. A murabaha is a cost-plus-profit arrangement that complies with Islamic finance standards. The exclusive oil-shipper for Saudi Aramco last year signed a deal to buy five very large crude tankers with shipbuilders Hyundai Heavy Industries. The move by OPEC's top exporter to expand its own fleet of VLCCs is to challenge regional rival Iran that boasts one of the world's largest fleet of oil tankers. It has 42 VLCCs and the world's 21st largest tanker fleet ahead of Saudi Arabia as well as Qatar, Oman and the UAE, according to the United Nations' 2015 Maritime Transport report.