St. Louis (AP) — Ameristar Casinos Inc. is laying off workers at its St. Charles and Kansas City casinos as part of a national reduction in work force.

Rebecca Theim from Ameristar’s corporate office in Las Vegas said workers were notified Friday. She said Ameristar tried various measures to avoid layoffs, but they weren’t enough in the worsening economy.

Ameristar’s casino and hotel in St. Charles will lose 6 percent of its staff. Its casino and hotel in Kansas City will lose nearly 5 percent. Workers were offered severance packages.

In addition, some other workers have until Nov. 21 to decide if they can stay with the company but work part-time.

Ameristar’s staff nationwide is being reduced by 4.5 percent.