LONDON (Reuters) - Financial services firms in Britain turned more optimistic for the first time this year as a drop in business bottomed out, but big uncertainties remained about COVID-19 and a post-Brexit trade deal, according to a survey published on Thursday. A drop in profits for banks, finance companies and building societies was partly offset by growth in earnings from insurance and investment management, the quarterly survey by the Confederation of British Industry showed. “While it is reassuring to see business volumes begin to stabilise in a sector so vital for the UK’s recovery, financial services isn’t out of the woods just yet,” Rain Newton-Smith, the CBI’s chief economist, said. Staff numbers fell less severely than in the previous three-month period and the decline was expected to slow again. Investment excluding technology was likely to fall in the year ahead, weighed down by the deepest demand uncertainty in eight years caused by COVID-19 and unresolved trade talks between Britain and the European Union. Non-performing loans grew but at a slower pace than earlier in 2020. The survey was conducted between Sept. 1 and Sept. 19 and 133 firms replied.