Dubai's Emirates Group has seen a "measurable slowdown" in business due to the coronavirus outbreak and has asked staff to take paid and unpaid leave, according to an internal email seen by Reuters.

Emirates Group, a state-owned holding company that counts Emirates airline among its assets, had more than 100,000 employees, including more than 21,000 cabin crew and 4,000 pilots, at end-March 2019, the end of its last financial year.

"A particular challenge for us right now is dealing with the impact of the COVID-19," the email to staff said, using the name of the disease caused by the coronavirus SARS-CoV-2.

"We've seen a measurable slowdown in business across our brands, and a need for flexibility in the way we work."

The email asked staff who have "accrued a significant balance of annual leave" to consider taking paid leave. It also said the company was offering unpaid leave to employees in non-operational roles and may offer it to operational staff.

"In all cases, we strongly encourage you to take up this opportunity if you have the support and approval of your line manager," the email said.

An Emirates spokeswoman confirmed the email had been sent to employees but declined to comment further.

Emirates Group's holdings also include dnata, which operates airport services and travel agencies around the world.

Global airlines have warned of the toll on their businesses from the coronavirus outbreak that first emerged in China in late December and has since spread to more than 50 countries.

Emirates has canceled all flights to mainland China, except to capital Beijing, and to Iran at the direction of the United Arab Emirates' aviation regulator, because of the spread of the virus in those two countries.