A new report from the London Assembly has found that the decision to close Visit London and create a new tourism and promotional agency for the capital has cost around £5m.
Mayor Boris Johnson launched the new London and Partners "super agency" - taking on the roles of Visit London, Think London and Study London - in April this year.
However, the assembly's Economy, Culture and Sport (ECS) committee has found that the cost of rescuing Visit London's pension scheme was £3m after it went into administration.
A further £2m went on start up costs for London and Partners, while the committee has also said the decision-making process had not fully considered the consequences of the move.
ECS committee chair Dee Doocey said: "While the mayor did the right thing in eventually agreeing to bail-out the Visit London pension scheme, it should never have come to that."