By Alistair Smout
LONDON (Reuters) - A slump in Admiral shares dragged Britain's top share index down further from the 14-month highs it hit on Wednesday, after the car insurer said that market volatility caused by Britain's vote to leave the EU had hit its solvency ratio.
Shares in Admiral, which slightly missed analyst estimates with its results, were down 8.5 percent, on course for their biggest fall since November 2011. Admiral also warned of additional risks from the Brexit referendum result from economic uncertainty and interest rate and forex volatility.
"Although the pre-tax profit of 189.5m pounds was in line with our forecast, it represented a small miss against consensus, itself a rare occurrence for Admiral," analysts at Shore Capital said in a note.
"However, it was the 'noise' around the group's Solvency II position, which dropped sharply in H1 16, and Brexit which were the most worrying, to us, and does question the wisdom of Admiral's return-of-capital strategy."
The stock was the stand-out faller on Britain's FTSE 100, which was down 14.01 points, or 0.2 percent, at 6,879.91 by 0835 GMT, after ending lower on Tuesday.
The mid-cap FTSE 250 was down just 0.1 percent.
Indivior surged 17 percent to an all-time high after its drug for opioid use disorder passed its latest clinical trials.
Infrastructure firm Balfour Beatty (LON:BALF) rose 7.5 percent after beating first-half expectations and resuming dividend payouts. It said there was little sign as of yet of the Brexit vote affecting its markets, but that it was too soon to know how the decision would eventually play out.
"The big news from Balfour Beatty this morning is the reinstatement in the dividend," said Stephen Rawlinson, analyst at Edison Investment Research.
"With the order book up 11 percent at 12.4 billion pounds, the legacy contracts well understood and in many cases resolved and with both risk and cash management under tight control, it is perhaps appropriate that the shareholders get the benefit of the improvement earlier than many expected."
Fellow construction firm CRH (LON:CRH) rose 2.8 percent, the top gainer on the blue-chip FTSE 100.
The biggest mid-cap faller was tech firm Laird, down 6.5 percent, after Cobham (LON:COB) announced that Laird's boss would replace the Cobham CEO by the end of the year.
Defence company Cobham's shares were up by 3.9 percent.