* Post-Brexit plans still in early stages
* Unclear how many jobs will be affected
* Roles could transfer to other European financial capitals
* Deutsche has signalled commitment to London post-Brexit
FRANKFURT, July 6 (Reuters) - Deutsche Bank is evaluating whether to move a large part of its securities trading business from London to Frankfurt or elsewhere in Europe as it prepares for Britain's exit from the European Union, a source told Reuters on Thursday.
Germany's largest lender is considering creating a booking centre for non-UK transactions which are currently reported through London, the person said on condition of anonymity because talks are ongoing and the plans not yet finalised.
Deutsche Bank will make changes as Brexit negotiations unfold, but the bank is preparing for a worst-case Brexit scenario that could entail a loss of so-called passporting rights between Britain and the EU, the person said.
Bloomberg News first reported details of plans for the booking centre on Wednesday.
A handful of banks have recently said that they were setting up subsidiaries in Frankfurt as they prepare for Brexit, including Nomura Holdings Inc and Daiwa Securities Group.
It remains unclear how many of its staff could be moved in the implementation of such a plan over the next 18 months and Deutsche Bank is also exploring the option of transferring some roles to Berlin or other financial capitals in Europe.
However, Deutsche Bank board member Sylvie Matherat suggested in April that it could move as many as 4,000 employees out of London as a result of Brexit.
Its annual report showed it employed 8,575 people in Britain out of 99,744 worldwide at the end of 2016, with about 5 billion euros in revenue coming from the UK out of 30 billion globally.
Deutsche Bank has signalled a vote of confidence in the British capital despite Brexit, informing staff in March that it had chosen a new office for its London headquarters slated to open in 2023. (Reporting by Tom Sims; Editing by Maria Sheahan and Alexander Smith)