(Fortune) -- Catherine West, EVP, Chief Operating Officer of J.C. Penney (Charts), ranks No. 46 on Fortune's 2006 list of 50 Most Powerful Women.

Penney's new COO - she's had the job since August - will help the $19 billion department store expand. The company plans to add 175 new stores to its 1,000-plus locations by 2011. Well positioned to grab market share after Federated's acquisition of May, Penney is also extensively remodeling its existing stores.

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: Ginni Rometty, IBM (Charts); Ellen Kullman, DuPont (Charts); Pat Woertz, Archer Daniels Midland (Charts); Lisa Weber, MetLife (Charts); Martha Stewart, Martha Stewart Living Omnimedia (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