Last week several British companies pulled ads from Facebook when they appeared on a page of the right-wing British National Party. Now they’ve beenjoined by the British government, which is concerned about how and where its ads are displayed. On Facebook, ads appear on pages on a rotating basis, which means advertisers have little sayover where they content appears. The government’s Central Office of Information (COI), the government’s advertising arm, said it was awaitingassurances from Facebook that its ads would reach desired audiences. It already has those from MySpace and Bebo. “Advertising has been paused temporarily on any Web sites that have not provided COI and [online media buying agency] i-level with the further assurancesour bookings require,” said Jamie Galloway, COI director of digital media. The COI has said it will not resume advertising on Facebook until the safeguards it seeks are in place. The government joins Vodafone, Halifax PLC, the AA, Virgin Media, First Direct Bank and Prudential, who withdrew their ads fromFacebook last week.