COLLEGE STATION, Texas -- Texas A&M fired football coach Kevin Sumlin on Sunday after six seasons and a 51-26 overall record.

Assistant coach Jeff Banks will serve as interim head coach, but sources told ESPN that Texas A&M will pursue Florida State coach Jimbo Fisher with a lucrative offer.

Sumlin's firing came less than 24 hours after the Aggies ended their regular season with a 45-21 loss to LSU to drop to 7-5 overall.

Texas A&M owes Sumlin a $10.4 million buyout under the terms of his contact, which is to be paid in the next 60 days and isn't reduced if he takes another coaching job.

"Kevin's tenure included some remarkable achievements and he leaves our program as one of the winningest football coaches in our storied history," Texas A&M athletic director Scott Woodward said in a statement. "Kevin made us a better all-around football program and led our program with dignity and character. He's a first-class person.

"Our expectations at A&M are very high. We believe that we should compete for SEC championships on an annual basis and, at times, national championships. I believe that we need a new coach to take us there. On behalf of Aggies everywhere, my thanks to Kevin and his family for his service to Texas A&M. I wish him the very best."

In his six seasons, Sumlin compiled the second-best winning percentage (.662) in the modern era of Texas A&M football. Since 1950, only R.C. Slocum (123-47-2, .721) has a better winning percentage than Sumlin in A&M history.

While Sumlin found success in the win column, the trajectory at which that success occurred ultimately sealed his fate. His best season in Aggieland was his first, an 11-2 campaign in 2012. After that, the Aggies failed to win double-digit games again.

The Aggies also didn't have a winning SEC record after their initial 6-2 mark in 2012, going 4-4 four times and 3-5 once. The most damning marks against Sumlin were his team's record vs. SEC teams at Kyle Field (8-14 overall, including a current seven-game losing streak to SEC West teams at home) and the Aggies' record against SEC West teams since Heisman Trophy-winning quarterback Johnny Manziel left the school (8-16 in the past four seasons, 16-20 overall).

"Every year is different," Sumlin said on Saturday after the loss to LSU. "I think in a way, we established a standard and kind of came on the scene right off the bat. Because of that, you look at trends. That's what people look at. Our trend is we flattened out from a wins standpoint, based on having the best player in the country the first year, first couple years. That's part of it."

The team's inability to succeed in key November games (the Aggies are 4-11 against SEC opponents in November since 2013) was also a point of contention for fans and alumni.

Coming into this season, Sumlin was well aware of the stakes because Woodward spelled them out explicitly in May. At the annual SEC coaches meetings in Destin, Florida, Woodward said on The Paul Finebaum Show that Sumlin "has to do better than he has done in the past."

That meant better than 8-5, which was the Aggies' record for three straight seasons entering 2017. While the team showed early signs of possibly improving on that mark with a 5-2 start, a 2-3 finish eliminated that possibility.

Regardless of the trajectory, Sumlin said that he felt good about what he achieved. When he arrived, the two coaches who preceded him were a combined 57-53 over nine seasons, and Texas A&M was considered an underdog as it left the Big 12 for the SEC. During Sumlin's tenure, the program spent more than $520 million on football facility renovations, including a $485 million redevelopment to Kyle Field. The program finished with a top-15 recruiting class nationally five times in six recruiting cycles.

"No matter who you are or what you do, you can live with yourself if you leave something better than what it was when you got there, whatever you do for a living," Sumlin said. "To be able to move into a new league, and probably, arguably, the toughest division in the toughest league in the country, never have a losing season, watch the renovation of Kyle Field, watch the change of culture into really, a national brand. The things that may or may not have been there before I got there, you go to sleep at night knowing that things are in a better place than certainly when I got here six years ago."

In eight seasons in Tallahassee, Fisher has guided Florida State to an overall 83-23 record. The Seminoles won the ACC three straight seasons from 2012 to 2014 and the BCS national championship in 2013. The team (5-6, 3-5 ACC) will wrap up the regular season on Saturday against Louisiana-Monroe.