Burger King has posted better-than-expected earnings and raised its full-year profit forecast. But the fast food giant said costs related to a restaurant renovation program would weigh down margins in the current quarter. The firm has been renovating older outlets and expanding value menu items and business hours in a bid to catch up with rivals. And it has also announced plans to launch an £85 Kobe beef burger in some high class restaurants in London. The diversification of the menu have helped the chain post stronger same-store sales growth than big rivals such as McDonald's and Yum Brands, which own Pizza Hut and KFC "Same-store sales in the United States killed McDonald's and Yum," said Stifel Nicolaus analyst Steve West. The world's second-largest hamburger chain on Thursday said net income rose to $41 million in the third quarter before March 31 – which is up from $34 million a year earlier. Total margins declined from a year earlier, as lower margins in the United States and Canada more than offset gains from other markets.