Restaurant Brands International reported mixed third-quarter results on Thursday, as Popeyes' struggles offset a strong showing from Burger King's U.S. business. Shares fell about 2% in morning trading, according to CNBC.

The company reported net income attributable to common shareholders of $542 million, or $1.54 per share, up from $315 million, or 96 cents per share, a year earlier. Excluding certain noncash items, it earned $1.10 per share. Across all its restaurants, same-store sales rose 3.8%, the fifth straight quarter of growth above 3%.

Burger King was the top performer, with U.S. same-store sales up 8.4%. CEO Josh Kobza told CNBC that sales of nuggets, which Burger King relaunched on Sept. 1 with 100% white meat chicken, have risen more than 35% since then. Chair Patrick Doyle said on the earnings call that Burger King "has delivered over four years of industry outperformance."

Popeyes lagged. Its U.S. same-store sales fell 2.2%. Kobza said on the earnings call that the company now expects Popeyes to return to same-store sales growth later than it previously forecast, though traffic is improving. He said the return of the $6 Big Box promotion in September lifted sales less than expected.

Tim Hortons reported 1.8% same-store sales growth in Canada. Restaurant Brands' international business posted same-store sales growth of 3.9%.