Public companies are taking advantage of soft directors and officers liability insurance rates and other market factors to increase their limits, brokerage Marsh Inc. said in a report released Wednesday.

More than one-third—33.9%—of Marsh clients that are publicly traded companies have increased their D&O limits this year, while only 2.1% decreased them, according to the October edition of “Marsh Insights: Benchmarking Trends.”

The percentage of companies boosting their D&O limits is the highest since 2008, when 24.2% bought higher limits, according to the report.

Organizations are upping their D&O limits in a marketplace that has been relatively soft for the past eight quarters, Marsh said. Other factors, such as excess insurance capital, continued profits for most professional liability insurers, and relatively stable class action claim trends contribute to a favorable marketplace where buyers can add to their limits while keeping overall costs stable, the report concludes.

Increasing regulatory scrutiny also may be prompting organizations to buy more coverage. Laws such as the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, which contains whistle-blower provisions, are increasing D&O exposures, according to the report.

Large and midsize companies have increased their limits more than small organizations. The report says 41.1% of companies capitalized at $10 billion or more increased their D&O limits this year. Among organizations with $2 billion to $10 billion in capital, 42.9% bought more coverage.

Among smaller companies with $301 million to $2 billion in capitalization, 30.3% increased their D&O limits, while only 18% of those with capitalization up to $301 million bought additional limits.

The trend likely will persist as companies face a “changing and increasingly active regulatory environment,” according to the www.marsh.com report. “Additionally, general soft market conditions are expected to remain throughout 2011, providing an opportunity for insureds to achieve improved terms and conditions and/or increased limits while maintaining costs.”