Chubb Limited CB reported first-quarter 2016 operating income of $2.26 per share, which surpassed the Zacks Consensus Estimate of $2.19 by 3.2%. Earnings improved year over year by a penny.The outperformance was fueled by strong operating and underwriting results. However, adverse forex effect hurt the bottom line by 5 cents in the quarter.Adjusted for one-time items, net income came in at 97 cents per share, down 53% year over year.Net premiums written improved 46% year over year to about $6 billion in the quarter. Net premiums earned increased 69% year over year on solid underwriting discipline. Renewal retention rates remained sturdy although adverse forex effect and integration-related activities posed challenges.Net investment income was $674 million, up 22% year over year.Property and casualty (P&C) underwriting income totaled $612 million, up 52% year over year. However, combined ratio deteriorated 160 basis points over the prior-year quarter.Segment UpdateNorth America Commercial P&C Insurance: Net premiums written declined 3.7% year over year to $2.8 billion. Combined ratio improved 140 basis points to 85.2%.North America Personal P&C Insurance: Net premiums written increased 6.8% year over year to $971 million. Combined ratio improved 1390 basis points to 92.3%.Overseas General Insurance: Net premiums written decreased 9% year over year to $2.3 billion. Combined ratio deteriorated 270 basis points to 92.2%.North America Agricultural Insurance: Net premiums written decreased 27% to $64 million, attributable to lower premium retention. Combined ratio deteriorated 390 basis points to 80.6%.Global Reinsurance: Net premiums written decreased 26.3% to $201 million. Combined ratio deteriorated 410 basis points to 80.6%.Life Insurance: Net premiums written increased 5.1% to $516 million. International life insurance net premiums and deposits collected improved 3.3% in constant dollars.Financial UpdateCash balance was $1.1 billion at quarter end, down from $1.8 billion at 2015 end. Total shareholders' equity was $45.9 billion, up from $29.21 billion at 2015 end.Book value per share at quarter end increased 10.1% from 2015 end to $98.85 at Mar 31, 2016.Operating cash flow came in at $1.0 billion.Looking ForwardChubb estimates integration expense savings of about $750 million by 2018, up from the prior guidance of $650 million.The company also expects investment income to improve by $100 million to $120 million before tax by the third or fourth quarter. Quarterly investment income is projected between $820 million and $840 million for remainder of the year.Zacks Rank and Other StocksChubb carries a Zacks Rank#3 (Hold). Among other the P&C insurers that have reported their first-quarter earnings so far, the bottom line at RLI Corp. RLI and First American Financial Corporation FAF surpassed their respective Zacks Consensus Estimate, while Progressive Corp. PGR missed the same.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report RLI CORP (RLI): Free Stock Analysis Report CHUBB LTD (CB): Free Stock Analysis Report PROGRESSIVE COR (PGR): Free Stock Analysis Report FIRST AMER FINL (FAF): Free Stock Analysis Report To read this article on Zacks.com click here.