The six Gulf Cooperation Council (GCC) states which heavily rely on oil earnings are expected to post a shortfall of $318 billion in 2015 and 2016 Kuwait Financial Centre (Markaz) said in a report.

The GCC groups Bahrain Kuwait Oman Qatar Saudi Arabia and United Arab Emirates.

Their public finances have been hit hard since oil prices shed more than two thirds of their value since mid-2014.

Oil income made up over 80 percent of public revenues in GCC states before the price decline.

Markaz said that GCC states will finance their deficits partly through borrowing and the rest by tapping their huge fiscal reserves.

OPEC kingpin Saudi Arabia last year borrowed $26 billion from local banks and used over $100 billion of its reserves that stood at $732 billion at the end of 2014 the report said.

With the exception of Oman and Bahrain GCC states have huge fiscal reserves and a low level of public debt allowing them to raise large volumes of domestic and international debt the report said.

The GCC states posted a combined deficit of $160 billion last year compared to a surplus of $220 billion in 2012.

In an earlier report in February Markaz expected GCC public debt to rise to 59 percent of gross domestic product (GDP) in five years from 30 percent at the end of 2015.