PURCHASE, N.Y. — PepsiCo, Inc. will transition to new leadership over the next several months in some of its key North America units, continuing a changing of the guard at the Purchase-based company that began earlier this year when Ramon Laguarta took over as c.e.o. of PepsiCo, Inc. from Indra K. Nooyi.

Albert P. Carey, chief executive officer of PepsiCo North America, has announced his intent to retire at the end of March 2019.

A 37-year-veteran of PepsiCo, Mr. Carey had been c.e.o. of PepsiCo North America since 2016. When Mr. Carey was promoted to that position, PepsiCo said it was bringing the company’s three North America businesses — North America Beverage (N.A.B.), Frito-Lay North America (F.L.N.A.) and Quaker Foods North America (Q.F.N.A.) — under a single leader to enable the company to further leverage its complementary brand portfolio across snacks, beverages and nutrition to unlock new growth opportunities.

Earlier, Mr. Carey had been c.e.o. of N.A.B. In addition to leading N.A.B., he has held various senior roles across snacks, beverages and food service during his career, including c.e.o. of F.L.N.A., c.o.o. of PepsiCo Beverages and Foods North America, senior vice-president of sales for Pepsi-Cola North America, c.o.o. of F.L.N.A., president of F.L.N.A.’s West business unit, and general manager of F.L.N.A. Foodservice.

“Al has been an invaluable leader, colleague, adviser and friend and will be missed by all of us at PepsiCo and all of the customers and partners he worked with over his exemplary career,” Mr. Laguarta said.

With Mr. Carey’s retirement, PepsiCo will return to its earlier model of separate leaders for its North America units, with Vivek Sankaran and Kirk Tanner taking over as c.e.o.s of F.L.N.A. and N.A.B., respectively.

Mr. Sankaran, currently president and c.o.o. of F.L.N.A., has been promoted to c.e.o. of F.L.N.A. Since joining PepsiCo in 2009, Mr. Sankaran has held senior leadership positions spanning snacks, Power of One customers, and corporate strategy, including as chief commercial officer for PepsiCo North America, chief customer officer for F.L.N.A., senior vice-president and general manager of F.L.N.A.’s South business unit, and senior vice-president of corporate strategy and development. Prior to joining PepsiCo, he was a partner at McKinsey, where he advised Fortune 100 companies with a focus on retail and technology.

Mr. Tanner, currently president and c.o.o. of N.A.B., has been promoted to c.e.o. of N.A.B. A 26-year veteran of PepsiCo with experience across snacks, beverages and food service, Mr. Tanner has worked in 11 domestic and international locations during his PepsiCo career and held numerous leadership roles across sales, operations, customer marketing, distribution and channel development.