Revised margin guidance upwards: Shares of Insurance Australia Group Ltd (ASX: IAG) moved up 6.4%, after announcing the review of its reserve releases. IAG has completed a preliminary review of prior period reserve releases for the financial year ended 30 June 2017 (FY17) as part of its regular year end processes, and indicated an outcome equivalent to a minimum 5% of net earned premium (NEP) against the previous guidance of 2% of NEP. The reserve releases predominantly relate to Australian long tail classes, comprising CTP, liability, professional risks and workers’ compensation. The higher indicated outcome, compared to previous expectations, reflects further favorable experience against underlying assumptions for claim size and inflation.As a result of the expected increase in reserve releases, IAG has raised its reported margin guidance range from 10.5-12.5% to 13.5-15.5% for FY17. Further, other underlying assumptions behind IAG’s FY17 reported margin guidance are unchanged, including net losses from natural perils of $850 million.