DUBAI (Reuters) – Abu Dhabi’s Etihad Airways has approached banks to raise over $500 million to finance four Boeing 787 Dreamliners it previously ordered, two sources familiar with the matter said.

The state carrier sent a request for proposals to banks last week for the financing, which is likely to be provided through bilateral loans or loans involving a small club of lenders, they said.

Etihad declined to comment.

It is common for airlines to approach banks to help finance aircraft deliveries.

Loans for 787s generally have a maturity of 12 years, the sources said, adding that the financing would likely be provided by Abu Dhabi banks.

Etihad operates a fleet of 26 787s and had a further 45 still to be delivered as of December 2018, according to Boeing’s website.