Julie Sweet will become the new chief executive of Accenture, the consulting firm announced on Thursday, adding another female leader to the senior-most ranks of the corporate world.

With Ms. Sweet’s appointment, 27 women will be leading companies in the S&P 500. That figure is up slightly from a year ago, but still means that just slightly more than 5 percent of the most valuable public companies in the United States are led by women.

Ms. Sweet, a former lawyer who is currently Accenture’s head of North America, will bring a measure of stability to the firm, which has been without a permanent leader for most of the year. In January, Pierre Nanterme stepped down as chief executive, citing poor health. Mr. Nanterme led the company for eight years, significantly enlarging Accenture’s market value, influence and head count.

Accenture’s chief financial officer at the time, David Rowland, was tapped to serve as interim chief executive while the board conducted a search for a full-time replacement. Mr. Nanterme died in January.