Staying nimble to move quickly in and out of various types of coverage remains a cornerstone of surplus lines insurer operations.

The agility is an antidote for the shifting of standard-lines insurers in and out of business areas where surplus lines writers might be operating. That is one of the biggest issues nonadmitted insurers say they currently face--the entry of admitted insurers into their market areas.

For buyers, that likely means a downward shift in price for some coverage lines as admitted insurers add their capacity. Additionally, standard markets are more likely to compete on price than are nonadmitted insurers, say several surplus lines observers.

The increased competition from standard insurers means surplus lines insurers must create new programs by aggregating similar risks, finding new niches that are underserved and looking to those hard-to-place risks that admitted insurers traditionally stay away from--no matter the overall market conditions.

Several of the top U.S. nonadmitted insurers say they are taking those measures in the generally soft market.

But not all lines of business are experiencing softening or an entry of standard lines insurers. Some are flat, and in catastrophe-prone areas there may be as much as a 50% shortfall in underwriter capital, one insurer estimated.

Some surplus lines insurers say they currently see opportunity in the heavy demand for catastrophe coverage.

But for others still feeling the impact of 2005's catastrophes, reducing their aggregate in storm-exposed regions remains the order of the day.

Next year could be completely different depending on how this year's storm season shapes up, surplus lines insurers say.

If insurers don't sustain heavy losses this year, those that have pulled their capacity could be looking to move back into storm-prone areas.

That could also mean that capacity that flowed from surplus lines property writers into casualty lines would shift back again, insurers add. That would drive up general liability rates.

Surplus lines insurers will be watching to see how they must respond with their capacity.

Following are profiles of the 10 largest surplus lines insurers as ranked by Business Insurance, including descriptions on how each is dealing with the various issues that are facing the market.

Some grew last year, others saw the premium volume they underwrite remain flat, while still others shrank, though in some cases the reduced premium volume was attributable to internal decisions to move certain lines of coverage to other units owned by their parent corporations.