LONDON (Reuters) - A former fund manager at the London division of asset manager BlackRock Inc <BLK.N> on Wednesday pleaded guilty to two counts of insider dealing in a London court.

Mark Lyttleton, 45, admitted buying shares shortly before public announcements about EnCore Oil Plc and Cairn Energy <CNE.L> after working on deals or on the basis of conversations with colleagues, the Financial Conduct Authority (FCA) said.

Lyttleton, who had been charged in September with three counts of insider dealing after being arrested in 2013, dealt through an overseas asset manager trading on behalf of a Panamanian registered company.

He will be sentenced at Southwark Crown Court on Dec. 21.

Lyttleton worked at BlackRock Investment Management (UK) Ltd between 2001 and 2013, according to the FCA's register of financial appointments.

Blackrock, the world's largest asset manager, reiterated that it had been told by the FCA that the charges related to alleged actions carried out for personal gain, while off its premises. There was no impact to any of its clients, it said.

Insider dealing is a criminal offense in the UK and is punishable by a fine and up to seven years in jail.

The markets regulator has secured 30 insider dealing convictions since starting to prosecute the crime in 2009.

(Reporting by Kirstin Ridley, editing by Louise Heavens)