MONROVIA, March 18 (Reuters) - Firestone Natural Rubber Co which operates the world’s largest single natural rubber plantation in Liberia, said on Monday it will be laying off 13 percent of its workforce or around 800 Liberian employees.

The announcement is the latest blow to one of the West African country’s largest employers, which began reducing production at its rubber wood factory last September in response to falling rubber prices.

These cuts will happen over the second quarter of this year, it said.

In a statement, Firestone said the lay-offs are “necessary due to continued and unsustainable losses resulting from high overhead costs associated with the company’s concession agreement with the government of Liberia, low natural rubber production because of the country’s prolonged civil wars and continued low global natural rubber prices.”

Global rubber prices have fallen by more than 40 percent since January 2017 and are now only slightly above historic lows. Firestone most recently laid off over 400 workers in 2016, again crediting the decision to falling rubber prices.

Firestone, an indirect subsidiary of Bridgestone Americas, signed a 99-year contract with the Liberian government in 1926. Its plantation covers almost 200 square miles east of the capital Monrovia. (Reporting by James Giuhyue Writing by Cooper Inveen Editing by Tim Cocks and Chris Reese)