FORT LAUDERDALE, Fla. (AP) — Four months after the country's largest auto dealership chain named a new chief executive to replace its longtime CEO, it's making another change at the top.

Chief Financial Officer Cheryl Miller is the new CEO at AutoNation, replacing Carl Liebert, who came to the company from the USAA financial services firm in March.

Executive Chairman and former CEO Mike Jackson said Tuesday that everyone knows the risks of hiring someone from outside. "Carl and I had an ongoing discussion, and it was a mutual conclusion that it was just not the right fit," Jackson said on CNBC.

Jackson stepped down four months ago after leading the 325-store company for 20 years, and Liebert, who had been chief operating officer at the USAA and had worked as an executive at The Home Depot and General Electric, was named as his replacement.

It's always difficult for an outside executive to adapt to a company's unique culture, but even more so with an outsized personality and strong presence like Jackson still around, said Autotrader.com Executive Analyst Michelle Krebs.

"Mike Jackson is a force of nature and he still obviously is very active in the business," she said. "That's always going to be difficult for someone."

Now it's something that will have to be dealt with by Miller, who has been with the Fort Lauderdale, Florida, company since 2009 and has been CFO since 2014.

AutoNation also promoted longtime executive and head of sales Jim Bender as chief operating officer.

Jackson said in a prepared statement that Miller has extensive knowledge of automotive retail with experience at the Alamo and National car rental brands before coming to AutoNation. She is the first female CEO of a publicly traded auto dealership group, according to the company.

She takes over the company at an extremely challenging time for auto dealers and the entire industry, according to Krebs. New car sales are starting to tail off after peaking in 2016, and consumers are changing the way they buy, doing more online preparation that cuts into the dealer's role, she said. Plus, the market eventually will shift toward electric and then autonomous vehicles, which will require big changes in the way dealers operate, Krebs said.

"We are on the verge of a transformation all up and down the line in the industry," Krebs said. "Dealership groups are in the same boat as automakers. "You've got to stay very focused on today's business and wring out as much profit as you can so you can invest in whatever the future holds."

AutoNation Inc. on Monday reported second-quarter earnings of $100.8 million.

On a per-share basis, the Fort Lauderdale, Florida-based company reported net income of $1.12. Earnings, adjusted for asset impairment costs and to account for discontinued operations, came to $1.20 per share.

The results surpassed Wall Street expectations. The average estimate of eight analysts surveyed by Zacks Investment Research was for earnings of $1.08 per share.

Shares of the company rose nearly 11 percent to $46.55 Tuesday.

_____

Portions of this story were generated by Automated Insights (http://automatedinsights.com/ap) using data from Zacks Investment Research. Access a Zacks stock report on AN at https://www.zacks.com/ap/AN