Royal Bank of Scotland Insurance is to set up its executive headquarters on the seventh floor of Churchill's Bromley offices.
The insurance giant is reported to have demolished ex-chairman Martin Long's suite of offices and is replacing it with space for Annette Court's management team.
The decision has been seen as further distancing Martin Long from the new organisation, while it will be a boost to Churchill workers, many facing redundancy following the takeover.
Churchill recently had to apologise to hundreds of IT staff who are due to be laid off after an advertisement for IT contract workers appeared on a recruitment website.
An insider said: "The company said it was a mistake and immediately took the ad down, but it did seem like they wanted to replace us with temporary staff."