Flat insurance rates in the excess and surplus lines market are drawing competition from the standard admitted market amid abundant capacity. Despite last month's Napa, California, earthquake, most experts say property catastrophe rates remain soft, while casualty and general liability rates are increasing somewhat.

Patrick Donnelly, president and deputy CEO of JLT Specialty Insurance Services Inc., said capacity is at “unprecedented” levels, which is resulting in competition on rates and terms and conditions to keep clients.

The E&S market is healthy but “is probably not growing as much as it could be in an otherwise more difficult market environment,” said Robert J. Greenebaum Jr., Chicago-based executive vice president of the casualty group practice at Swett & Crawford Group Inc.

Joel Cavaness, president of Itasca, Illinois-based managing general agent Risk Placement Services Inc., said the market is in transition.

“It's soft in some spots, a little more firm in some spots, depending on the region or line of business that you're in,” Mr. Cavaness said. The general trend is “going from a little harder to a little softer,” he added.

Jamie Crystal, executive vice president of New York-based brokerage Crystal & Company, said rates “are renewing as expiring, or with a slight reduction, typically in the 1% to 2% range.”

Rates are “being driven by the traditional non-E&S insurers that have been moving fairly aggressively into what traditionally has been E&S placements,” which are “now being written directly by large insurance companies,” he said.

This is leading E&S insurers to “either become more competitive or find other areas in which to build their premium volume,” such as environmental, cyber and real estate company coverage, he said.

Linc Trimble, Jersey City, New Jersey-based executive vice president of e-commerce at Torus Insurance Holdings Ltd., said business now being written by admitted insurers includes risks with unusual exposures, such as a restaurant with a marina or mechanical rides, or a hotel with a pool that has a water slide.

The E&S market, though, is “still decently disciplined, probably with the exception of catastrophic property, which continues to be relatively soft in nature,” Mr. Cavaness said.

Property catastrophe rates are all over the board based on factors including size and type of risk, but overall are down about 15%. The Napa quake has not yet had any effect on the market, he said.

Maureen Caviston, Stamford, Conn.-based president and chief operating officer of wholesaler Partners Specialty Group L.L.C., said the quake has had “no impact at all.”

Lana S. Parks, president of wholesaler The Parks Group Inc. in Arlington, Texas, said Texas is one area where property rates have increased in the past 18 months.

With the exception of Superstorm Sandy, “Texas leads the nation in weather-related losses,” Ms. Parks said of property rates that have increased an average of about 10%.

While overall property rates have declined about 5%, casualty coverage has seen “very, very modest rate increases” depending on the class of business, said James Drinkwater, property/casualty brokerage division president of AmWINS Group Inc. in New York.

F. Marshall Turner II, president and CEO of Alpharetta, Georgia-based insurer Maxum Indemnity Co., said general liability rate increases “are certainly slowing, but we're still seeing some low- to mid-single-digit positive movement.”

For professional errors and omissions coverage, rates range from “very low single-digit decreases” to similar-size increases, he said.

However, professional liability rates are “not going to go through the floor because the losses from 2008 and 2009 have not been fully paid yet,” said Christopher J. Cavallaro, managing director at Jericho, New York-based wholesaler ARC Excess & Surplus L.L.C. More competition will drive down rates over time, he said.

Despite the buzz caused by the announcement of its entry into the E&S market in June 2013, Omaha, Nebraska-based Berkshire Hathaway Inc.'s presence has not been disruptive, experts say.

Berkshire Hathaway has been equal parts aggressive and disciplined as it assumes “the place in the market that they believe they should hold,” Mr. Donnelly said.

“The nice thing about Berkshire Hathaway is they're a responsible competitor,” said Bryan Sanders, president of Glen Allen, Virginia-based wholesale broker Markel Corp.

The outlook is positive for buyers, Mr. Crystal said.

Buyers are “going to benefit from a favorable insurance marketplace,” with the outlook for some broadening in terms and conditions and/or reductions in pricing where many saw modest increases over the past couple of years, he said.

“Capacity will continue to be abundant,” Mr. Drinkwater said. “Absent a major event, we're probably going to see prices continue to be competitive.”