Jim Calhoun, who 26 years ago took over perhaps the weakest program in the Big East and transformed it into one of the most prominent in the nation, is retiring.

As first reported by NBC Connecticut, Calhoun is expected to formally announce his retirement after 40 years of coaching – 26 at UConn – at a press conference on Thursday.

It is expected that assistant coach Kevin Ollie will take over the head coaching reins, at least for the interim.

Calhoun has waffled on his decision since last season ended in March, saying that he intended on coaching out the final two years of his contract but reserved the right to change his mind. A broken hip suffered in a bike accident in early August may have been the final straw in determining that, at age 70, it was time.

Calhoun won three national titles at UConn and took the team to four Final Fours. He finishes with 873 career wins (sixth on the all-time list) – 625 of them at UConn. He was inducted into the Naismith Memorial Basketball Hall of Fame in 2005.

The Huskies won the national championship in 2011 behind a miraculous performance by Kemba Walker, but have otherwise been hit with plenty of controversy in recent years. Low Academic Progress Rate (APR) scores will keep UConn out of the postseason this year. A few years ago, the program was also docked scholarships due to recruiting violations.

Calhoun has also battled numerous health problems in recent years, from cancer (prostate and skin) to broken ribs and a broken hip from bike accidents.

As he has indicated in the past, Calhoun is expected to remain with the program in some capacity. According to his 2010 contract extension, he was due to receive either a one-time payment of $1 million or secure employment in a full-time position in the athletics department for a maximum of five years at an annual salary of $300,000.

Ollie has never been a head coach at any level and has only been a UConn assistant for two seasons since retiring from a nomadic, 13-year NBA career. However, Calhoun has been privately lobbying for Ollie to be named as his successor, though first-year athletic director Warde Manuel has balked about naming Ollie a “coach-in-waiting.”

According to reports, Ollie will be given a one-year contract but will not be labeled an “interim” head coach. Associate head coach George Blaney will remain on the staff, as well as assistant Glen Miller. Director of basketball operations Karl Hobbs will be bumped up to assistant status, as well.

Ollie has drawn rave reviews among recruits. Contacted Wednesday evening, Kareem Memminger, the AAU coach of recent UConn commit Kentan Facey, said: “If Kevin takes over, we will still honor the commitment. Anybody else, we’ve got to look at it.”

Ollie has huge shoes to fill. Calhoun is one of only five college basketball coaches in NCAA history to win three national titles (1999, 2004, 2011).

Calhoun began his collegiate coaching career at Northeastern in 1972 and took that program to the NCAA tournament five times before taking over the reins at Storrs in 1986.

After a 9-19 inaugural season, Calhoun’s UConn teams never finished below .500 again over the next 25 years. They won the National Invitational Tournament in 1988, and two years later won their first Big East tournament title while riding a “dream season” to the Elite 8.

UConn won seven more Big East tourney titles under Calhoun and 10 regular-season championships. The program reached the Sweet 16 13 times under Calhoun and got to the Elite Eight nine times.