Mark Lyttleton, 45, of Belsize Avenue, will spend Christmas behind bars after abusing his position at the world’s biggest finance firm.

A former manager in BlackRock’s £2 billion UK Absolute Alpha fund has been jailed for 12 months for selling shares through his wife’s Panamanian registered company.

Wealthy Lyttleton did not need the cash and his actions were described as “the idiot frolics of a former golden boy on his way down”, Southwark Crown Court heard yesterday.

Lyttleton dealt in shares and ‘call options’ in EnCore Oil Plc and Cairn Energy Plc between October and December 2011 using inside information.

He had knowledge that one of the companies would soon be taken over and that the other had failed to discover oil in Greenland.

Having obtained that information, the court heard he then instructed Caldwell and Partners to trade in stocks on behalf of a Panamanian-registered company, Huduno, set up in his wife’s name.

The court was told Lyttleton made around £45,000 from the EnCore trading but lost approximately £10,000 from Cairn.

Lyttleton was regarded as a ‘hero’ after taking a £100million portfolio and turning it into $4.5billion before it fell to $1billion putting him under ‘extreme stress’.

Judge Andrew Goymer said he had “no doubt” that Lyttleton knew what he was doing and had breached the “trust and respect” given to him by his employers.

Judge Goymer added that the company did not lose any money of Lyttleton’s actions. The judge also ordered the confiscation of £149,861.27 and ruled that Lyttleton must pay £83,225.62 in court costs within 28 days.

If he fails to do so he will face another 18 months behind bars.

Lyttleton admitted two counts of insider trading and was sent to prison for 12 months.