Aetna chief to step down

The chairman and CEO of one of the nation's largest health insurance companies is stepping down.

Aetna announced Wednesday that Ronald Williams will retire in April 2011. Williams will become executive chairman on Nov. 29, with current president Mark Bertolini taking over as CEO and joining the board of directors on that date before taking over as chairman in April. 

Williams has been with Aetna for almost 10 years. Bertolini joined the company in February 2003 and heads its business operations. 

Aetna is one of the nation’s leading diversified healthcare benefits companies, serving approximately 35.8 million people.