A company executive has been found guilty of touching and squeezing a woman’s bottom as she travelled on a busy tube train.

James Froomberg, 62, a former National Lottery commissioner, was charged with sexually touching the woman on the Central line on 1 May, while her boyfriend was nearby. The jury sitting at London’s Blackfriars crown court took two hours and 20 minutes to reach its unanimous verdict.

Froomberg, of Edgware, north London, had claimed he was asleep and denied sexual assault. He is to be sentenced on 12 October after the judge has received pre-sentence reports.

The judge, Rajeev Shetty, thanked the jury and told them it was unlikely that Froomberg would go to prison but that he could be facing a community order.

The judge told Froomberg, who was bailed until sentencing: “I cannot promise you, as you will appreciate, what the sentence will be, but I have alluded to what the appropriate starting point might be.”

In summing up, the judge had reminded the jury of the woman’s claim that a person touched her “over a few minutes and squeezed her bottom”. He said: “The prosecution say that the person who did this was the defendant. It was intentional.”

The court was told that Froomberg was sleeping during the evening rush-hour journey. Shetty added that Froomberg said “he cannot have done what he is accused of”.

Both the woman and her boyfriend claim that two other passengers – a man and a woman who have not been identified and did not give evidence in court – had said there had been touching.

The woman’s boyfriend held Froomberg outside Mile End station until police arrived.

Froomberg had said he had just come from a long steak and chips lunch with former colleagues, where he had probably had up to two bottles of wine. He said he only remembered leaving the lunch and being jolted awake on the tube. He said he rushed away but did not believe he touched anyone.

Froomberg had been a leisure and property industry director with more than 20 years’ experience in the private, public and consultancy sectors, and was the chairman of Young Enterprise London by the time he was appointed as a National Lottery commissioner in January 2008. He was also a corporate development director at Wembley PLC and a partner at KPMG.