(Fortune) -- Paula Rosput Reynolds, CEO and President of Safeco (Charts), ranks No. 40 on Fortune's 2006 list of 50 Most Powerful Women.

Reynolds spent 27 years in the energy industry - and ran $2.7 billion AGL Resources - before taking charge at the property and casualty insurer early this year. Her task at the $6.2 billion company: to expand its market share outside its home territory, the Pacific Northwest.

By the key criteria Fortune uses in assembling its annual list - the size, importance, and health of each business in the global economy, and the momentum of each woman's career (along with her social and cultural influence) - there's no question that the power of women in the corporate sphere is rising.

Indeed, it could be called the year of the Most Powerful Woman CEO. The top seven positions on Fortune's 2006 Most Powerful Women list are held by CEOs.

Some other powerful women on the list include: Sallie Krawcheck, Citigroup (Charts); Ann Livermore, Hewlett-Packard (Charts); Charlene Begley, General Electric (Charts); Pat Woertz, Archer Daniels Midland (Charts); Linda Dillman, Wal-Mart (Charts); and Meg Whitman, eBay (Charts).

Next: Full list: 50 Most Powerful Women at //money.cnn.com/popups/2006/fortune/mostpowerfulwomen/1.html

Plus: Most Powerful Women: 10 Highest-Paid at //money.cnn.com/popups/2006/fortune/womenpay/index.html