DUBAI, May 17 (Reuters) - Abu Dhabi National Oil Company (ADNOC) has started virtual meetings with potential investors ahead of the planned initial public offering of its drilling unit, two sources told Reuters. Banks working on ADNOC Drilling are scheduling calls with a local, regional and international institutional investors to sound out appetite for the potential sale, said the sources, declining to be named as the matter is not public. The meetings are described as an early look engagement, one of the sources said, where the company that is set for a public share-sale is introduced and feedback is sourced from investors. ADNOC, which supplies nearly 3% of global oil demand, declined to comment when contacted by Reuters on Monday. (Reporting by Hadeel Al Sayegh, editing by Louise Heavens) Our Standards: The Thomson Reuters Trust Principles.