(CN) — Charles and David Koch are suing Venezuela to collect $409 million awarded by an international arbitration panel.

In a federal complaint filed Nov. 28 in Washington, D.C., two companies owned by the billionaire brothers, Koch Minerals Sarl and Koch Nitrogen International Sarl, say they have not been paid an award granted them in October by the International Centre for Settlement of Investment Disputes, after then-President Hugo Chavez expropriated FertiNitro in 2010.

At the time, Koch Minerals Sarl indirectly owned 25 percent of the equity of FertiNitro, which operated two fertilizer plants located in Jose, Venezuela.

Koch Nitrogen International Sarl had a long-term agreement with FertiNitro to purchase, at a discount, both ammonia and urea.

The Tribunal found that Venezuela unlawfully expropriated the two companies interests in FertiNitro. It awarded Koch Minerals Sarl $140,250,000 in principal compensation, and Koch Nitrogen International Sarl $184,800,000.

The Tribunal also awarded the two companies pre-award interest. The amount of pre-award interest awarded to Koch Minerals Sarl came to $28,419,011.14, for a total of US$168,669,011.14.

The amount of pre-award interest awarded to Koch Nitrogen International Sarl came to $37,446,226.44, for a total of US$222,246,226.44.

A request for comment made to the Venezuelan Embassy in Washington was not returned.