PURCHASE, N.Y. — Solid operating and sales performance at Frito-Lay North America, Quaker Foods North America and Latin America Foods led to an 8% gain in operating profit within the PepsiCo Americas Foods unit of PepsiCo, Inc. in the third quarter ended Sept. 3. At $1,370 million, operating profit for PepsiCo Americas Foods was up from $1,271 million in the same period a year ago. Net revenue in the division also increased, rising 8% to $5,628 million from $5,193 million.

For the nine months ended Sept. 3, operating profit within PepsiCo Americas Foods was $3,823 million, up 8% from $3,531 million, while revenues rose 6% to $15,761 million from $14,835 million.

F.L.N.A., the largest segment within PepsiCo Americas Foods, posted a 6% gain in operating profit during the third quarter to $918 million. Net revenue also was higher, climbing 4% to $3,173 million from $3,050 million.

“F.L.N.A. volume increased 1% and net revenue grew 4% in the quarter driven by strong growth in club, convenience, dollar and drug channels,” PepsiCo said. “Lay’s, Doritos, Cheetos and Ruffles posted strong revenue growth driven by innovation and price realization as the division executed its planned pricing actions in the quarter. Operating margins expanded in the quarter reflecting the benefits of net revenue growth and productivity.”

For the nine months ended Sept. 3, F.L.N.A. operating profit was $2,545 million, up 6% from $2,394 million in the same period a year ago. Net revenue was $9,167 million, up 3% from $8,906 million.

Third-quarter operating profit at Q.F.N.A. rose to $177 million, up 6% from $167 million in the same period of fiscal 2010. Net revenue was up 2% at $614 million, which compared with $601 million a year ago.

“Strong effective net pricing led to net revenue growth and operating profit growth,” PepsiCo said. “Both gross margins and operating margins expanded in the quarter, reflecting strong effective net pricing and solid cost controls offsetting commodity inflation.”

For the nine months ended Sept. 3, Q.F.N.A. operating profit was $558 million, up 7% from $521 million, while net revenue eased 2% to $1,837 million from $1,866 million.

Latin America Foods posted the sharpest increase during the third quarter, as operating profit rose 15% to $275 million and net revenue jumped 19% to $1,841 million.

“Volume grew 3.5% in the quarter reflecting solid gains in the division’s largest markets, Mexico and Brazil, and strong growth in a number of key markets across Central and South America,” PepsiCo said. “Growth was driven by a strong innovation agenda, successful brand promotions, consumer value initiatives and marketplace execution. Strong price realization led to double-digit revenue and operating profit growth, although operating profit growth was impacted by higher commodity inflation.”

For the nine months ended Sept. 3, Latin America Foods operating profit was $720 million, up 17% from $616 million in the same period of fiscal 2010. Net revenue also rose 17%, climbing to $4,757 million from $4,063 million.

Overall, net income at PepsiCo, Inc. in the third quarter totaled $2,011 million, equal to $1.25 per share on the common stock, up 4% from $1,930 million, or $1.19 per share, in the same period a year ago. Net revenue was $17,582 million, up 13% from $15,514 million. For the nine months, net income was $5,060 million, or $3.14 per share, up 2% from $4,977 million, or $3.06 per share, in the same period a year ago. Net revenue was $46,346 million, up 17% from $39,683 million.