In a statement, JJB said it was 'naturally disappointed' with the ruling and was sticking to its claim that 'it did not infringe competition law' when selling Umbro shirts in 2003.
A spokeswoman said that the company - which yesterday revealed flat pre-tax profit of£18.2 million for the 26 weeks to July 30 - had to lodge its intention to appeal with the House of Lords today.
She added that after doing this the retailer would 'take time to examine its options and then decide whether to proceed with the appeal to the House of Lords'.
Initially, JJB was fined£8.4 million by the OFT but, at a hearing at the Competition Appeal Tribunal in May last year, that was cut to£6.7 million.
The company revealed in its interim results yesterday that it had increased the amount it had set aside to cover any possible fine from£2 million to£3.88 million.