BOGOTA (Bloomberg) -- Colombia is planning to hedge its oil exports to protect the government from the violent swings in revenue it suffered in recent years.

The financing bill to be presented to Congress Wednesday proposes the creation of a fund that can buy derivatives from “foreign entities specialized in operations of this type,” according to a copy of the bill seen by Bloomberg. The bill needs to be passed by Congress to become law, and would take effect on Jan. 1.

Oil is Colombia’s largest export accounting for about a third of the total. The crash in prices in 2014 and 2015 forced the government to raise value added tax to cover the hole in its fiscal accounts, and led in 2017 to the nation’s first rating downgrade in 15 years. Colombia produces about 860,000 bopd.

The fund can’t issue debt, and the nature of hedging operations means that losses are possible, according to the bill.

Mexico buys options which gives it the right to sell oil at a certain price, protecting the country from a sudden price drop. In 2015, Mexico pocketed a record payout of $6.4 billion after crude prices crashed. For next year, the country has already spent $1.2 billion on hedging.

The government of President Ivan Duque, which took office in August, has a strong alliance to get laws through Congress. At the same time, it’s not clear that lawmakers will grasp the benefits of a stabilization fund, said Camilo Perez, chief economist of Banco de Bogota.

In the past, Colombian governments have been deterred from operations of this kind for fear of being accused of causing losses to the nation, Perez said. Other measures in the bill, such as the extension of value added tax to food staples, are likely to face opposition.