UK private equity firms Livingbridge and CBPE Capital are close to wrapping up their latest funds, but question marks remain over fundraising in the second half of the year as investors gauge the impact of Britain's decision to leave the European Union.

London-based Livingbridge has so far collected £600 million from investors for its latest vehicle, according to people familiar with the matter. The fund, which doesn't have an upper limit yet, is expected to close at about £650 million in August, one person said.