JD Sports, Elite Sports and Rangers Football Club have been fined £2million for fixing prices of football shirts.
The Competition and Markets Authority (CMA) said Elite Sports and JD Sports broke competition law by fixing prices of Rangers-branded replica kits and other clothing.
Elite Sports has been fined £459,000, JD Sports £1.4million and Rangers £225,000.
JD Sports and Elite fixed prices between September 2018 and July 2019.
Rangers is a Glasgow-based football team with strong support in Scotland and Northern Ireland.
Rangers FC also did fixed prices, but on one item: adult home short-sleeved replica shirts, which it did from September 2018 to mid-November 2018.
All three firms colluded to stop JD Sports undercutting the retail price of the shirt on Elite’s Gers Online store, the CMA said.
The firms got lower fines for co-operating with the CMA.
CMA executive director or enforcement Michael Grenfell said: "At a time when many people are worried about the rising cost of living, it is important that football fans are able to benefit from competitively priced merchandise.
"Instead, Elite, JD Sports and, to some extent, Rangers, worked together to keep prices high.
"Today’s decision sends a clear message to football clubs and other businesses that illegal anti-competitive collusion will not be tolerated."
Elite made Rangers-branded clothing and other products, which it sold through its Gers Online store, as well as bricks-and-mortar shops in Glasgow and Belfast.
The only UK-wide major retailer selling those products at the time was JD Sports.
Rangers became concerned that JD Sports was selling its Rangers replica tops at less than Elite was during the 2018 to 2019 football season.
The CMA said Rangers was unhappy because Elite was its retail partner at the time.
This led to an agreement between all three firms that JD Sports would raise the price of its Rangers adult short-sleeved home replica shirt.
JD Sports hiked the price of this shirt by nearly 10%, from £55 to £60, to bring it in line with the prices being charged by Elite on Gers Online.
The CMA also found that Elite and JD Sports – without involvement from Rangers – colluded to fix the retail prices of Rangers-branded clothing, including training wear and replica kit, over a longer period.
This included aligning the level and timing of discounts towards the end of the football season in 2019, to avoid competition between them and protect their profit margins.
A JD Sports statement said: "JD has co-operated fully with the CMA throughout this investigation, including taking swift steps to apply for leniency and agreeing to settle the investigation.
"As a consequence, the CMA has applied a substantial discount in determining its final penalty of £1.485million. In accordance with the CMA's standard terms of settlement, JD will not be appealing against this penalty.
"No directors or senior management of JD were involved in the offending conduct, which took place in 2018-2019.
"JD has taken a number of steps to strengthen its competition compliance programme and is committed to ensuring that this is embedded into its daily operations."
Elite and Rangers FC have been approached for comment.
Earlier this year Elite and JD Sports applied for leniency during the CMA’s investigation and confessed to cartel activity.
