The average number of board committees among S&P 1500 companies has remained relatively stable at 4 committees per corporate board over the three-year period from 2008 to 2010, according to executive compensation data firm Equilar.

“Among S&P 1500 boards, the majority of boards (68 percent) have either three or four committees (2010). The most common committees are, unsurprisingly, the audit, compensation, and governance committees,” it said in the 2011 Board Composition Series Report.

Overall, nearly 99 percent of S&P 1500 companies have established the three minimum board committees as required by the listing standards set by the New York Stock Exchange and NASDAQ. And 31 percent of that group have expanded on the basic requirements by creating five or more committees to cover areas such as executive, finance, compliance/regulatory, strategy, technology, and environmental, health & safety.

Even with the additional committees created by this sub-group of companies, Equilar said the average number of board committees had remained flat at 4.1 (2008-2011) while the group of boards with six or more committees had grown from 10 percent in 2008 to 11 percent last year.

Looking at company size, Equilar found that larger-cap firms typically have more committees per board, an average of 4.7, compared to the mid- and small-cap groups of companies that have an average of 4 and 3.7 committees, respectively.

“Smaller companies are more likely to have fewer board committees. This aligns with our findings that small-cap companies typically have smaller boards than their mid- and large-cap peers,” it said. The research also noted that smaller boards usually have fewer committees, and much of the work was performed in committees handled by the entire board.

When comparing the number of committees across different industries, the research firm found that businesses in highly regulated industries, such as utilities and financials, have more committees than companies in other industries.

The utilities industry has an average of 5 committees, followed by financial with 4.6 in 2010. The number decreases among companies in industries with fewer regulations such as technology (3.8) and services (3.9) in the same year.

“Utilities boards often have separate committees tasked with overseeing compliance, regulatory, or public policy issues,” it said.