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May 13 (Reuters) - Sherritt International S.TO said on Wednesday its external auditor has resigned and finance chief has left, adding that these developments would delay first-quarter financial filings and could trigger a halt in trading of its shares in Canada.

The Toronto-based miner has been recently hit by a U.S. executive order expanding sanctions against Cuba that also targeted Moa Nickel, a joint venture between Sherritt and Cuba's state-owned nickel company.

Following the U.S. order on May 1, Sherritt suspended direct participation in the joint venture in Cuba.

The Canadian mining and energy company said on Wednesday Deloitte has resigned as its auditor effective May 12 and that it has begun the process to appoint a replacement.

Sherritt said the resignation was not the result of any disagreement over accounting principles, financial disclosures or audit procedures.

Deloitte's reports on the company's previously issued financial statements "did not contain any adverse opinion or a disclaimer of opinion," the company said.

Sherritt also said Yasmin Gabriel has resigned as its chief financial officer effective Thursday. The miner did not give a reason for her departure or name a successor.

As a result of these resignations, the company said it expects it will be unable to file its first-quarter financial statements by May 15.

The U.S. executive order could weigh on the willingness of some audit firms to work with Sherritt, the company said.