Delta Air Lines says it will continue to keep middle seats open in its planes, effectively reducing capacity by nearly one-third, for the rest of the year. (Star Tribune/The Minnesota Star Tribune)

Delta Air Lines will continue blocking middle seats through the winter holidays, but flights will soon be more full.

Starting in October, the Atlanta-based airline will increase capacity limits in coach from 60 to 75% while extending its blocked middle-seat policy through Jan. 6.

Delta, the dominant carrier at Minneapolis-St. Paul International Airport, said Thursday it will open up additional aisle and window seats and will allow families to book seats next to each other beginning Oct. 1.

The airline's executives have repeatedly said that while 6 feet of distance between passengers isn't possible on airplanes, empty seats offer at least some extra space that — along with the wearing of face masks — helps reduce the risk of spreading the coronavirus.

"Medical experts, including our own partners at Emory Healthcare, agree — more distance on board makes a difference," Bill Lentsch, Delta's head of customer service, said in a statement.

During the pandemic, Delta has tried to position itself as the health-and-safety U.S. carrier. While other airlines, including Southwest, Alaska and JetBlue have also limited seat sales, Delta's largest rivals, American and United, have not.

The capacity cap in the first-class cabin will remain at 50% through Oct. 31. On flights without a middle seat, Delta will block one aisle of seats from front to back.

"We believe that taking care of our customers and employees and restoring confidence in the safety of air travel is more important right now than filling up every seat on a plane," Lentsch said. "We'll continue taking a thoughtful, layered approach ensuring customers know to expect the highest standard of care as they prepare for their holiday travels."

The coronavirus pandemic has suppressed air travel for much of 2020 with U.S. passenger volumes last week 71% below a year-ago levels, according to Airlines for America.

While some flights are much more full than others, the average U.S. flight last week was at 48% capacity, compared to 87% during the same week last year.

The new capacity limit for coach will again be re-evaluated at the end of October and could change soon thereafter. If it is further raised or removed, it's possible a flight could be nearly full even with Delta's blocked middle seat policy still in place.

That's because middle seats will now appear available for groups of three or more people booking seats on the same itinerary. Middle seats will remain blocked for solo passengers and parties of two through at least Jan. 6.

Kristen Leigh Painter • 612-673-4767