PepsiCo, Inc. said yesterday that Chief Financial Officer Indra K. Nooyi will replace Steven Reinemund as chief executive officer of the soft-drink and snacks company, making her the no.2 female CEO in the Fortune 500.

With her October 1 appointment, Ms. Nooyi takes her place in an elite group of 11 female CEOs running Fortune 500 companies. Patricia Woertz, at agricultural processor Archer Daniels Midland Co., ranks first. ADM is ranked 56th in the Fortune 500, while PepsiCo, the world’s second-largest soft-drink company after Coca-Cola Co., is ranked 61st.

“I’m very excited and at the same time very humbled,” Ms. Nooyi told analysts during a conference call on yesterday morning.

Ms. Nooyi said she felt fortunate to be taking over at a time when PepsiCo was in such a strong position, with solid growth across all its business units. She and Mr. Reinemund have worked closely during the last five years, and Ms. Nooyi described their relationship as one in which they complete each other’s sentences.

“Indra Nooyi is truly a star and has been working side by side with Mr. Reinemund over the past several years,” Citigroup analyst Bonnie Herzog wrote. “She has been very involved with every major decision PepsiCo has made over the past five-plus years and therefore we expect this transition to be very smooth.”

Mr. Reinemund said in a statement that he is retiring to spend more time with his family.

“I can’t tell you how excited I am to pass the baton to Indra,” Mr. Reinemund said yesterday.

Wall Street analysts said they were surprised mainly at how early the transition is being made.

“While we are surprised by this move, PepsiCo’s deep bench gives us confidence that the strong momentum the company has delivered should continue,” Morgan Stanley analyst William Pecoriello wrote.

Mr. Reinemund was a driving force in diversifying PepsiCo’s product portfolio into healthier foods, Bank of America analyst Bryan Spillane writes. The company’s growth has been bouyed by strength in non-carbonated beverages and in international markets, moving its focus away from the flagship cola products. Sales of non-carbonated drinks, such as Aquafina water and Gatorade, surged 23% in North America in the most recent quarter.

Mr. Reinemund, 58, will continue as chairman of the board until his retirement in May 2007. He has worked for Purchase, N.Y.-based PepsiCo for 22 years, serving as chairman and CEO for five.

Ms. Nooyi, 50, has been with the company since 1994 and has been CFO since 2001. She will be the fifth CEO in Pepsi-Co’s 41-year history. Mr. Pecoriello said he had the “highest confidence” in Ms. Nooyi’s ability to lead the company forward. In her current position, she had a primary role in projects such as the spinoff of its bottling operations, its acquisition of Tropicana, and the purchase of Quaker Oats, the company said in a statement.

Pepsi reported a 14% rise in profit for the second quarter, and analysts predicted further growth. Profit for the quarter ended June 17 grew to $1.36 billion, or 80 cents a share, while revenue climbed 12% to $8.6 billion.