(ShareCast News) - Direct Line Group posted a 3.1% increase in total written gross premiums for the three months to 30 September, led by a 6.8% increase in Motor.That came alongside a 7% drop in total costs for ongoing operations, while investment income yield rose to 2.4%.For the nine months to 30 September total gross written premiums were up by 1.3%.The insurer reiterated its expectations for a full-year 2015 combined operating ratio of between 92% to 94% after normalising for major weather events.Underlying trends remained broadly in line with previous expectations for a combined operating ratio of between 94% to 96%.Paul Geddes, CEO of Direct Line Group, commented: "Our strategy is progressing well and we continue to see the benefits of our programmes to improve customer experience and differentiate our brands, with a strong performance in Motor helping us deliver overall growth in our gross written premium."At the same time, we have also realised further efficiencies throughout the business, with costs reducing 7.0% compared to the first nine months of last year."