COLUMBIA — The University of South Carolina’s self-imposed penalties and its cooperation with the NCAA turned out to be enough, as the NCAA decided Friday not to punish USC further for major violations of its rules, primarily involving the football program.

USC’s most significant self-imposed penalties were three years of probation, a loss of six football scholarships, a reduction of three scholarships for the incoming freshman football classes of 2013 and 2014 and a fine of $18,500. The NCAA accepted all the penalties and also cited USC for failing to monitor its athletic department — a charge USC agreed with.

The NCAA Committee on Infractions said it “decided not to impose more stringent sanctions in this case, including a postseason ban, because the cooperation exhibited by the institution went beyond its obligations under (NCAA bylaws), the violations were limited in scope, the institution self-imposed significant penalties and there was no unethical conduct in this case.”

USC self-imposed penalties in December while admitting major violations in its football program in 2009 and 2010. The school essentially pled guilty to all of the NCAA’s accusations, rather than trying to hide from them. And that was a major development in the case.

In February, USC representatives met with the Committee on Infractions in Los Angeles to discuss the case. The committee had the option of adding penalties, such as exclusion from bowl games, which it has done in other cases involving major violations.

“A university has a choice to make,” said the committee’s chairman, Britton Banowsky, who is the commissioner of Conference USA. “It was obvious to the (Committee on Infractions) staff that the university wanted to get to the truth. In some cases, they went beyond what the NCAA was doing (in the investigation).”

As part of an investigation that began in summer 2010, the NCAA charged USC with three major infractions in September: athletes receiving impermissibly discounted rates at a Columbia hotel, two USC graduates giving athletes and recruits improper benefits, and USC failing to monitor both situations, which the NCAA said resulted in athletes receiving $59,000 of improper benefits.

“The university regrets the past actions and decisions by individuals that resulted in violations of NCAA legislation,” USC athletic director Eric Hyman said in a statement. “We are pleased, however, that the Committee on Infractions found the corrective actions we have taken and the penalties we have self-imposed reflect the university’s commitment to full compliance with NCAA rules.”

The NCAA slightly tweaked USC’s scholarship reduction, while not eliminating more scholarships. The football team is normally allowed to carry 85 scholarship players. USC proposed that number be reduced to 84 next season, 82 in 2013 and 83 in 2014. The NCAA decided USC will play with 85 next season and 82 in both 2013 and 2014.

The NCAA made no other changes to USC’s self-imposed penalties and announced that the school’s three-year probation period began Friday. If USC violates NCAA rules during that period, it could face stricter penalties than it normally would.

USC’s other self-imposed penalties included a reduction in official recruiting visits, the disassociation of boosters and the demotion of the school’s compliance director.

Football is normally allowed 56 official recruiting visits per school year. But for 2012-13, that number will be 30. The track and field program, which was also involved in the violations, will be limited to 50 official visits in 2012-13. There is normally no limit for that sport.

USC self-imposed the $18,500 fine because four football players competed while ineligible in 2009.

USC stopped recruiting athletes associated with the Delaware-based Student-Athlete Mentoring Foundation, which is run by USC graduates Steve Gordon and Kevin Lahn, who provided impermissible benefits through the foundation.

Three USC coaches were involved to at least some degree with Gordon and/or Lahn but did not immediately report their actions to USC’s compliance office: former assistant men’s basketball coach Mike Boynton, quarterbacks coach G.A. Mangus and head track and field coach Curtis Frye. All three received official reprimands from Hyman.

Additionally, Boynton, who was fired along with head coach Darrin Horn after the season, wasn’t allowed to recruit off campus for a month. Mangus won’t get any bonuses next school year or a raise the following year. Frye was prohibited from attending the 2012 Penn Relays (a major event) and will get no bonuses this school year and no raise next year.

Frye and members of his team went on a dinner cruise paid for by Lahn, which resulted in extra benefits received by the athletes and Frye having impermissible contact with a recruit. Lahn was a member of the Gamecock Club, USC’s booster organization, before USC officially cut ties with him and Gordon because of the NCAA investigation. The SAM Foundation provided $8,000 in impermissible benefits to athletes and recruits, the NCAA said.

“The university failed to monitor and investigate the impermissible recruiting activity by boosters, according to the committee,” the Committee on Infractions said in Friday’s announcement. “Specifically, at least four athletics department employees (who the committee did not name) did not recognize the potential violations.”

USC in its self-imposed penalties demoted compliance director Jennifer Stiles, who incorrectly approved the reduced rate at The Whitney Hotel, which contributed to 10 football players and two women’s track and field athletes receiving impermissible benefits. The NCAA said the benefits from the Whitney Hotel part of the case totaled $51,000.

USC disassociated itself with Whitney general manager Jamie Blevins. Because the hotel was a member of the Gamecock Club when at least some of the violations occurred, the violations were deemed to be extra benefits.

USC could have faced harsher punishment as a repeat violator of NCAA rules. The football program committed major violations under coach Lou Holtz, who preceded current coach Steve Spurrier. The probation period stemming from those violations ended in 2008, for a case decided in November 2005. The Committee on Infractions had the option of invoking the repeat violator clause, because the recent violations occurred within a five-year window of that punishment.

But in the end, the committee gave USC credit for its openness in the investigation and decided to not drop the hammer.