According to executive search consulting firm Spencer Stuart, CFO tenure is on the rise among Fortune 500 CFOs. Average tenure is 5.9 years, up from 4.9 years since 2008. The increase in tenure is one of the trends highlighted in Spencer Stuart's annual CFO Index. The CFO Index looks at trends related to chief financial officers of Fortune 500 companies over an eight-year period.

While CFO tenure is climbing, there is also significant turnover taking place among the Fortune 500 CFOs. There were 16 more CFO transitions in 2012 (15%), compared to 2011 (11%). The consumer goods sector has seen the highest increase in turnover in the past four years with 18 transitions in 2012, while there has been less volatility in the financial services sector, which had the lowest number of CFO transitions in 2012 (6) since the CFO Index began tracking the data eight years ago.

"A number of CFOs, particularly in financial services companies, have been committed to seeing their companies through and past the financial crisis," said Joel von Ranson, leader of Spencer Stuart's North American Financial Officer Practice. "Now as markets continue to stabilize, it's likely CFO tenure will gradually return to its long-term average."

Along with an increase in tenure, there have also been modest gains for female CFOs. 11.4% of the Fortune 500 CFOs are women, compared to a CFO index low of 6.7% in 2006.

"The news for women aspiring to CFO roles is positive, but there still is considerable work to be done," said von Ranson. "The story is similar for people of color, who represent just 3.4% of CFOs today, which is down from a high of 4.0% in 2010."