Updated

One of Puerto Rico's largest unions is suing to block a federal control board's austerity plan that would slash pensions and other spending by the U.S. territory.

The suit filed Wednesday by the United Public Servants union says the plan violates a law protecting the pension system as well as constitutional guarantees involving contracts between the government and retirees.

The board's plan aims to save a pension system expected to run out of money this year. It would cut benefits for retirees who receive more than $2,000 a month.

A board spokesman did not immediately return a message for comment.

The union represents some 13,000 government workers and more than 2,000 retired ones.