Anti-capitalist protesters of the 'Occupy London' movement have vacated a building in the city's financial district less than a day after entering it, they said on Sunday.

'Occupy London' activists entered the abandoned nine-storey Roman House building -- formerly used by finance companies -- in the Barbican arts and conference centre in the early hours of Saturday.

But they left the premises later in the day after a request from contractors employed by the building's owners.

"Occupy London was contacted by individual workers employed by Berkeley Homes who were concerned for their job security as it transpired they were recently employed to help renovate the building," a statement said.

"In light of these discussions, yesterday evening it was decided to leave the building."

The protesters' brief occupation comes as 'Occupy London' prepares to appeal this week a London High Court move to approve a bid by authorities to evict members its members from outside Saint Paul's Cathedral.

The protesters -- who have been camped outside the landmark church since October 15 after taking their lead from anti-capitalist demonstrators in New York's Wall Street -- plan to appeal against the decision on Thursday.