Nottingham Forest said they were “extremely disappointed” by a four-point deduction that plunged them into the Premier League relegation zone, despite receiving a lesser punishment than Everton for breaching profitability and sustainability rules (PSR) because they admitted guilt early and fully cooperated with the independent commission.

Everton were given a 10-point deduction, reduced to six on appeal, for a £19.5m overspend, whereas Forest breached permitted losses of £61m by £34.5m. The commission believed Forest were worthy of the same punishment but said a potential six-point loss was reduced to four owing to the club’s “early plea and the cooperation together”. The Premier League had argued for an eight-point deduction.

Forest were left infuriated by the decision and process. They claimed spending restrictions on promoted clubs, whose permitted losses are reduced by £22m for each season across the three-year accounting period they spend in the EFL, undermined the league’s “integrity and competitiveness”. They have dropped to 18th, one point behind Luton, and are considering whether to appeal.

A Forest statement said: “We were extremely dismayed by the tone and content of the Premier League’s submissions before the commission … We believe that the high levels of cooperation the club has shown during this process, and which are confirmed and recorded in the commission’s decision, were not reciprocated by the Premier League.”

The commission rejected much of Forest’s mitigating evidence. One of the club’s key arguments related to the sale of Brennan Johnson. The forward was a key asset because, as an academy graduate, all money earned from his sale would count as profit. The club knew they would need to sell a player to comply with PSR by 30 June and described their failure to do so as a “near miss”. They received an offer for Johnson of €50m (£42.9m) on that date from Atlético Madrid but demanded €65m (£55.8m). Three offers were received from Brentford between early July and late August but all were rejected, before Johnson was sold on 1 September to Tottenham for £47.5m.

The commission believes the club could have done more to complete Johnson’s transfer by 30 June, with a number of teams interested, and that missing the deadline by more than two months could not be classified as a “near miss”.

Forest said: “The commission’s decision raises issues of concern for all aspirant clubs … There will be occasions when a player transfer cannot be completed in the first half of a transfer window andcan only be completed at the end of that window. This should not be a reason for the condemnation of a club. For this not to be recognised by the commission or the Premier League should be a matter of extreme concern for all fans of our national game.”

Premier League clubs are allowed to lose £105m over a three-year period but Forest’s permitted losses were limited to £61m because they spent two years of that period in the Championship. This was another part of their defence, with the club claiming they were hamstrung after being promoted because investment is vital to challenge at a higher level against more established teams.

“We were also surprised that the Premier League gave no consideration at all to the unique circumstances of the club and its mitigation,” Forest said. “In circumstances where this approach is followed by future PSR commissions, it would make it extremely difficult, if not impossible, for newly promoted clubs without parachute payments to compete, thus undermining the integrity and competitiveness of the Premier League.”

The commission said the punishment was “a proportionate sanction to maintain the integrity of the Premier League” and was designed “to give the public confidence that when a club invests as Forest did to compete in the Premier League, it still needs to comply with the PSR threshold for losses”.

Forest have seven days to appeal. There is a deadline of 24 May – five days after the season – for any PSR appeals to be concluded.