Southwest Airlines will offer assigned seats, ditching the open seating policy it’s had since its founding over 50 years ago

Southwest Airlines Co. will begin offering assigned seats, ditching the free-for-all policy that has been a defining feature of the carrier for more than half a century. The airline announced the seismic change to its business model Thursday alongside a new premium-class option and plans for redeye flights. While Southwest indicated earlier this year that it was reconsidering the seating policy, it’s now facing heightened pressure to revamp underperforming operations from activist investor Elliott Investment Management. The steps represent a strategic shift for the carrier, which has steadfastly maintained open...