By Florence Tan

Singapore, April 29 (Reuters) - Abu Dhabi National Oil Company (ADNOC) has informed some of its customers that it may ship two types of crude oil outside the Gulf region next month, given the continued closure of the Strait of Hormuz, according to two people familiar with the matter and a memo seen by Reuters.

These two types of crude oil are Das and Upper Zakum, which ADNOC will transport from the Das Island and Zirku Island terminals located within the Gulf to external loading sites.

Exports from the two terminals have fallen sharply, as it has been difficult to find ships willing to pass through the strait since the outbreak of war between the United States and Iran in late February.

ADNOC said in a note to customers, "To ensure customers can continue to execute contracted shipping operations, we are also providing shipments for loading outside the Arabian Gulf, on a case-by-case basis."

The memo did not mention how ADNOC plans to transport the shipments.

The producing company said customers can contact ADNOC staff to confirm their plans for shipping long-term cargo using alternative delivery points.

ADNOC has not yet responded to a request for comment.

The memo did not specify alternative delivery points, but the sources said they included ship-to-ship transfers off Fujairah in the UAE or off Sohar in Oman.

The sources added that ADNOC also did not mention whether these operations would entail additional costs, and whether these would be borne by the company or the buyer.