While the total market share of the 10-largest property-casualtyinsurance groups edged closer to 50 percent last year, the playingfield spread out a little bit more for commercial lines insurers in2006, according to figures compiled from a National Underwritersubsidiary, Highline Data. The same insurance groups comprised thetop 10, but some took slightly smaller pieces of the overallpie.

Indeed, the combined market share of the top 10 insurers–basedon direct written premiums for all lines of business, and acrossall regions–was 48.6 percent in 2006, information from regulatoryfilings published online in Highline Data's Insurance Analyst PROdatabase show.

According to Highline Data market share reports for the priortwo years, the same 10 insurance groups took slightly smallerslices of the overall pie, grabbing a 48.2 percent share in 2005and 47.9 percent in 2004.

For all lines of insurance and all regions combined, Omaha,Neb.-based Berkshire-Hathaway exhibited the greatest increase inmarket share among the top 10 groups–up 0.7 percentage points since2004. While three other groups–American International Group,Liberty Mutual Group and Nationwide–also had small gains, sharesfor all the other six groups tumbled.

Berkshire was the only group among the top 20 to recorddouble-digit growth in direct written premiums in 2006, and one ofonly four groups among the top 100 to post a double-digit jump inall three years.

All totaled, direct premiums for the industry grew just 3.1percent on average in each of the last three years, suggesting therest of the pack merely coasted along, barely keeping pace withgrowth in the overall economy (based on gross domesticproduct).

Tables attached to this story show the individual market sharesfor the last three years for each of the top-100 groups overall, aswell as the top 50 groups writing commercial lines, and the top 50personal lines groups.

While market shares, premiums, loss ratios and commission ratesshown are for all lines combined, and for all states andterritories taken together, similar reports are available forspecific lines, combinations of lines, single states or regions ofthe country.

Although Berkshire leapt over personal auto specialistProgressive of Mayfield Village, Ohio, to take eighth place in theoverall market-share ranking, the jump wasn't entirely attributableto that ubiquitous lizard hawking auto insurance for Berkshire'sGEICO companies.

In fact, the commercial lines market-share report reveals thatwhile the top 10 commercial lines writers lost 1.4 points of marketshare since 2004–with the top 10 share falling from 47.2 percent in2004 to 45.8 percent in 2006–Berkshire-Hathaway, now ranked 12thamong commercial writers, posted a market share gain of 0.7percentage points for commercial lines.

Digging deeper into the composition of Berkshire's commerciallines book reveals that much of the group's 22.1 percent growthrate in commercial lines direct premiums in 2006 is attributable tothe workers' compensation line.

Excluding workers' comp, Berkshire's direct premiums stilljumped 7.5 percent in 2006, with its biggest and smallest lines(commercial liability and commercial auto) showing declines, andits commercial property premiums nearly tripling.

While less than 30 percent of Berkshire's $4 billion incommercial direct premiums come from workers' comp, acquisitions inthe California comp market have fueled an average annual rate ofgrowth of 200 percent for the group in the last three years, and a2006 jump in premiums of 90.8 percent.

Ninety-three percent of Berkshire's $1.1 billion in comppremiums come from California–a state where the group wrote just$15 million in comp in 2003, and where the industry saw premiumsslide 17 percent in 2006 as a result of rate declines.

Berkshire-Hathaway's largest line remains personal auto, wherethe GEICO companies maintained a fourth-place ranking with over $11billion in direct premiums, growing just shy of double digits at9.9 percent in 2006.

For the industry overall, direct premiums for the personal autoline–growing by just 0.5 percent in 2006–depressed the overallpersonal lines growth rate. With the auto line accounting for 73percent of personal lines premiums, a 5.7 percent jump in the otherpersonal line–homeowners–was barely perceptible in the personallines totals, moving the sector's growth rate to just 1.8 percentoverall for 2006.

The property lines–homeowners and commercial property–were thebig gainers for the industry in terms of growth. While commercialauto direct premiums declined slightly, commercial property directpremiums soared 13.3 percent in 2006.

Even in property lines, however, premium growth rates forindividual groups and for the industry vary widely by region.

An accompanying summary table reveals some of the pain enduredby southern homeowners in recent years. In spite of widely reporteddecisions of major personal lines carriers to cut exposures inhurricane-prone states, direct premiums still jumped 9.7 per yearon average for each of the last three years in the South.

The South is also the only region where commission rates onhomeowners business showed an obvious slide–from 13.8 percent in2004 to 13.3 percent in 2006. In other regions, commission rateshovered around the same levels over the three-year period.

Meanwhile, pure loss ratios–direct incurred losses divided bydirect earned premiums–give some indication of the relativeperformance of insurance groups in terms of overall profit.

While these loss ratios varied widely in 2006, Chubb andTravelers posted the lowest personal lines loss ratios among thetop 20 insurance groups–each about a dozen points below theindustry average of 55. For commercial lines, Chubb and Berkshirewere the best performers, with loss ratios roughly 14 points belowthe industry's 49.4 ratio last year.

Direct premium, loss and expense information provided on thestate pages of the annual statement–from which the accompanyingmarket share exhibits were derived–do not include all of the lossadjustment and underwriting expense data needed to calculateinsurer combined ratios, which are a more complete measure ofprofitability.

(For more information about the data, contact Chris Rogers ofHighline Data at 617-441-5976.)