CHARLOTTE, N.C. -- The NFL's first choice is for the Carolina Panthers to remain in Charlotte under the next owner, league spokesman Joe Lockhart said Thursday during a media conference call.

Panthers owner Jerry Richardson announced Sunday that he plans to put the organization up for sale after the season. The NFL is investigating Richardson for allegations of workplace misconduct ranging from sexual harassment to directing a racial slur at a former team scout.

"The franchise in Carolina is successful both on the field and from a business perspective as far as community impact,'' Lockhart said. "So we think that it's very important that franchises, particularly ones that have achieved the success of the Panthers, stay in the market where they're playing.''

Lockhart said the Richardson investigation, which the league took over from the Panthers on Sunday, would be conducted by outside counsel. He said it would not include Lisa Friel, hired by the league to help with domestic violence investigations, such as the one involving then-Panthers defensive end Greg Hardy in 2014.

Lockhart also said the league was not aware of settlements the Panthers made with at least four people to keep Richardson's misconduct under wraps, as was outlined in a Sports Illustrated story published on Sunday.

"I don't believe the league was, but certainly that is an area that the investigation will look into,'' he said.

Lockhart said the league did not pressure Richardson to give up day-to-day control of the team or to sell. It was a decision by the Panthers on Monday to name Tina Becker as the chief operating officer.

Richardson's long-term plan before Sunday was that the team wouldn't be sold until two years after his death.

"I think he came to the conclusion over the weekend that putting the team up for sale is what he wanted to do,'' Lockhart said. "I think we found out about it shortly before the announcement went out.''

During the call, Lockhart outlined what the sale of the Panthers involved. He said the new controlling owner:

Is required to individually own at least 30 percent of equity. (Most owners typically own more than that, and some own 100 percent.)

Must to be able to demonstrate financial wherewithal to acquire and effectively operate the team.

Must have full voting control over all matters involving the club and stadium, including all football operations.

Cannot exhaust his or her (total) financial resources to make a bare-minimum equity acquisition.

Is limited to a maximum of $250 million in total debt related to the club. Other debt is permitted beyond that debt ceiling, but it has to be collateralized by non-football assets.

In addition to that:

The payment must be paid in cash or financed.

A new ownership group is limited to a maximum of 25 co-owners.

A public company or not-for-profit can't buy the team.

All owners must be approved by three-quarters (24 of 32) of member clubs.

Richardson originally purchased the team, which played its first game in 1995, for $206 million. Forbes in September valued the organization at $2.3 billion.

Richardson told team captains of his decision to sell after Sunday's 31-24 victory over Green Bay, which improved the Panthers' record to 10-4. Middle linebacker Luke Kuechly, one of those in the meeting, said "everybody was just surprised.''

Kuechly said the Panthers, who lost Super Bowls after the 2003 and 2015 seasons, want to send Richardson out with a Super Bowl victory.

"That would be the best way to send him off,'' Kuechly said. "Everybody wants to win the Super Bowl. It would be very meaningful for him.''

Tight end Greg Olsen said the meeting with Richardson was emotional.

"You felt for him,'' he said. "To see a guy who's worked his whole life to bring this organization to Charlotte and have him sit there and tell you and see it on his face how heartbreaking that is that he's going to give that franchise up to somebody else ... it's hard to see people in those positions. It's human nature. You don't want to see people struggle.''

The Associated Press contributed to this report.