The exchange said its British share trading was £5bn a day, on a par with the same period last year, while the volume of trades for the period was up 12 percent to 693,000 a day.
"We saw increases in trading volume across our cash equities, derivatives and fixed income businesses," said Rolet.
The LSE, which started exclusive takeover talks with its clearer LCH.Clearnet on Wednesday, said its fixed income and derivatives markets were up 11 percent while clearing activity rose 5 percent for the period.
Rolet has been keen to diversify the 200-year old exchange away from its main share trading business since his appointment in 2009 and has listed clearing and derivatives as key opportunities.
"Our diversification strategy is delivering. We expect the Group to report good first half results," Rolet said.
The LSE said it expects to announce interim results for the six months to the end of September on November16.