More than 300 pilots and flight attendants will lose their jobs, and Southwest Airlines is ending its open seating policy as part of major cuts, the company announced.

The Dallas-based airline said it will reduce staffing and cut flight routes in the Southwest region, according to a statement made by Southwest Airlines on Thursday. The changes will take effect in April 2025.

Southwest will cut routes from Atlanta to 16 cities across the U.S., according to company officials.

The airline said it hopes these changes will improve financial performance and increase shareholder value while enhancing the customer experience.

Southwest’s recent investor, Elliott Investment Group, which recently bought a stake in the airline, said the company has been underperforming.

“Southwest feels that it has to make these moves, especially the reductions in Atlanta, to improve profitability,” said Southwest CEO Bob Jordan during an event Thursday. “However, these decisions are impacting our flight attendants, the face of our airline, who have dedicated decades to Southwest.”

In addition to the staff cuts and route reductions, the airline will end its long-standing open seating policy, a hallmark of Southwest for more than 50 years. Assigned seats will now be prepaid. The company also plans to offer more international vacation packages.

Southwest said it expects these changes to generate an additional $1.5 billion in pre-tax earnings by 2027.