Paul Scholes has been fined and warned over his future conduct by the Football Association after placing bets worth £26,159 on football matches during his time as a director of Salford City.

The former Manchester United midfielder was found to have placed 140 bets over three and a half years, in contravention of the FA’s gambling rules. The FA said these included bets on the outcome of United matches – at a time when his former teammates and fellow Salford investors Ryan Giggs and Nicky Butt were working there – and one involving Valencia, when they were coached by Scholes’s friends and fellow Salford investors Gary and Phil Neville.

The FA fined Scholes £8,000 and asked him to contribute to the costs of the tribunal. It also accepted his argument that he had not been aware of the rules, which were tightened in 2014 to prevent anyone involved in the sport from betting on any football fixture.

In a statement, Scholes apologised for his conduct. “I accept [the] ruling. I would like to apologise and I understand and fully accept the fine imposed by the FA,” he said.

“It was a genuine mistake and was not done with any deliberate intention to flout the rules. I wrongly believed that as long as there was no personal connection between me and any of the matches that I bet upon then there would be no issue.

“However, I understand now that this is not the case and I should have taken steps to verify this at the time.”

The FA became aware of Scholes’s behaviour after being informed of his betting history by the bookmaker Paddy Power at the turn of this year. An investigation was launched and incorporated information from another bookmaker Bet365.

From 17 August 2015 to 12 January 2019 Scholes was found to have made eight bets on the outcome of Manchester United matches, one on a Valencia game and eight on FA Cup fixtures. The last of these was seen as the most serious breach; Salford are participants in the FA Cup, although they had been knocked out by the time Scholes placed each of the bets.

Scholes said he believed the rules applied only to matches in which the gambler might be able to affect the outcome. The FA accepted this argument but said that, as an “experienced former player”, he should still have understood the laws in full.

Scholes quit as a director at Salford in February to take on the manager’s role at Oldham Athletic (another club he had bet on). From the £26,159 gambled, Scholes made a net profit of £5,831.