A solicitor who took part in insider trading with his elderly father-in-law was jailed for eight months yesterday.

Christopher McQuoid, 40, committed the offence while acting in his professional capacity and in a position of trust, said Judge Peter Testar, passing sentence at London's Southwark Crown Court.

His father-in-law, James Melbourne, 74, was given the same sentence, but suspended for 12 months, owing to his age and the illness of his wife and son, the judge said.

The lawyer, from Fowlmere, Royston, in Hertfordshire, and his father-in-law, of Broadway, Ripley, in Derbyshire, were found guilty of one count of insider trading on Friday.

The defence revealed that this was the first case in which the Financial Services Authority, which prosecuted, had gone down the criminal route, rather than the regulatory route, under which various individuals had been fined.

The court heard during the trial that the pair made a £48,900 profit between them after McQuoid tipped off Melbourne that his phone technology employers were about to be taken over by US mobile giant Motorola.

Then, just before the deal was made public at the beginning of June 2006, the retired businessman spent more than £20,000 on 153,824 shares in TTP Communications plc.

When the London stock exchange announced the buy-out, the share price more than trebled. Just over a month after the buy-out, Melbourne sold his holding for £69,225.80 - a profit of £48,919.20.

On September 1, McQuoid received a cheque from Melbourne for exactly half the net profit.

The court heard that McQuoid had been an in-house solicitor for TTP, which developed technology for the mobile communications industry.

Among its customers was Motorola, which began "highly confidential merger discussions" with the firm in April 2006.

The court heard that Melbourne had not previously held shares in TTP and had no recent history of dealing in company shares.

Judge Testar said: "The evidence revealed deliberate and calculating behaviour on the part of both of you.

"This is not a victimless crime - this is a crime which does undermine confidence in the integrity of the market, and this is a confidence which is of great importance to the economic welfare of the community as a whole.

"In addition, it does seem to me that the public are entitled to be angry if people who are in possession of inside information treat that position as a licence to print a substantial amount of money."