The Saudi Stock Exchange has asked banks to pitch for roles advising on its initial share sale, sources familiar with the matter said, kicking off one of the region's most eagerly-anticipated flotations.

Tadawul said in December that it planned to list in 2018.

An invitation was sent out to local and international banks at the start of March asking them to submit bids to advise on the initial public offering, with responses due at the end of the month, two of the sources said.

Tadawul was not immediately available for comment.