Southwest Airlines is planning to reduce service to and from Atlanta next year, cutting more than 300 pilot and flight attendant positions, according to a company memo seen by CNBC.

The changes come a day before Southwest’s investor day, when executives will map out the company’s plan to cut costs and grow revenue as pressure mounts from activist investor Elliott Investment Management.

Southwest told staff it isn’t closing its crew base in Atlanta. Instead, it will reduce staffing by as many as 200 flight attendants and as many as 140 pilots, for the April 2025 bid month.

The airline also isn’t laying the crews off, but they will likely have to bid to work from other cities.

Southwest will reduce its Atlanta presence to 11 gates next year from 18, according to a separate memo from the pilots’ union.

It will service 21 cities from Atlanta starting next April, down from 37 in March, the carrier said.

“Although we try everything we can before making difficult decisions like this one, we simply cannot afford continued losses and must make this change to help restore our profitability,” Southwest said in its memo. “This decision in no way reflects our Employees’ performance, and we’re proud of the Hospitality and the efforts they have made and will continue to make with our Customers in ATL.”

The unions that represent Southwest’s pilot and flight attendants railed against the airline for the staffing and service cuts.

“Southwest Airlines management is failing Employees while impacting Customers. Management continues to make decisions that lack full transparency, sufficient communication with Union leadership, and most alarmingly, a lack of focus on what has made the airline great, the Employees,” said Bill Bernal, the flight attendants’ union president.

A Southwest spokesman confirmed the changes and said the carrier will “continue to optimize our network to meet customer demand, best utilize our fleet, and maximize revenue opportunities.”

The airline had already pulled out of certain airports, some of which it experimented with during the pandemic to focus on more profitable service.

Southwest is not only facing changing booking patterns and oversupplied parts of the U.S. market but aircraft delays from Boeing, whose yet-to-be-certified 737 Max 7 airplanes are years behind schedule

The airline’s COO, Andrew Watterson, told staff last week that it will have to make “difficult decisions” to boost profits.

The reduction in Atlanta, the world’s busiest airport and Delta Air Lines home hub, is the latest development for the airline. In July, Southwest announced it plans to get rid of open seating and offer extra legroom on its airplanes, the biggest changes in its more than half-century of flying.

Also on Wednesday, Southwest released an expanded schedule, selling tickets through June 4. In addition to the planned cuts in Atlanta, the carrier said it will boost service to and from Nashville, Tennessee. It will also start offering overnight flights from Hawaii, beginning April 8. Those include service from Honolulu to Las Vegas and Phoenix; Kona, Hawaii, to Las Vegas; and Maui, Hawaii, to Las Vegas and Phoenix.