UK business confidence improves after post-referendum slump - YouGov/Cebr

LONDON, Sept 2 (Reuters) - British businesses recovered some confidence about their prospects after a post-Brexit vote scare, but remained largely pessimistic about the economic outlook, a survey showed on Friday.

The proportion of businesses that were optimistic about their own prospects over the next 12 months rose to 48 percent in August, up from 46 percent in July, according to the monthly survey conducted by YouGov (LSE: YOU.L - news) and the Centre for Economics and Business Research (Cebr).

The overall confidence index reached 109.7 in August from 105.0 in July, regaining much of the ground it lost immediately after the UK voted to exit the European Union on June 23, when it fell from June's 112.6.

But companies remained downbeat about the economy in the next 12 months.

Although the proportion of pessimistic businesses fell to 45 percent in August from 49 percent in July, that was still well above the 25 percent posted in June, before the referendum.

Prime Minister Theresa May has said she will not start the formal divorce procedure from the EU by triggering Article 50 of the EU Lisbon Treaty until next year, to allow time to come up with a negotiating stance.

"Once the UK shows its hand on Brexit and invokes Article 50 things could change for the worse quickly," said Stephen Harmston of YouGov. "But as businesses and consumers don't know when this will happen, they have seemingly decided to just get on with it."

(Reporting by Laura Gardner Cuesta)