Growth at Burger King was driven by successful new products and promotions, including the Spicy BLT Whopper sandwich.

OAKVILLE, ONT. — The newly created parent company of Burger King and Tim Hortons reported a strong start to the fiscal year, as system-wide sales for both brands rose by high-single digits in the first quarter.

For the three months ended March 31, Restaurant Brands International Inc. suffered a loss attributable to shareholders of $8.1 million, which compared with $60.4 million, equal to 17c per share on the common stock, in the prior-year period. The company’s adjusted EBITDA, meanwhile, increased to $354.6 million from $159.7 million. Revenues for the quarter totaled $932 million, which compared with $240.9 million for the previous year.

“We were able to deliver positive comparable sales and net restaurant growth across both of our independently managed brands, creating value for our franchisees and plenty of opportunities for our employees,” said Daniel Schwartz, chief executive officer of Restaurant Brands International, during an April 27 conference call with analysts. “We’re encouraged by our first-quarter results but recognize that we still have tremendous opportunities to create value for all of our stakeholders for both brands for many years to come.”

Restaurant Brands International common shares began trading on the Toronto Stock Exchange and New York Stock Exchange under the trading symbol QSR on Dec. 15, 2014. The combined company has approximately $23 billion in system sales, with more than 19,000 restaurants in approximately 100 countries and U.S. territories.

During the first quarter, comparable sales increased 4.6% for Burger King and 5.3% for Tim Hortons, and system-wide sales grew 9.6% at Burger King and 8.1% at Tim Hortons in constant currency.

“This marked our best quarterly comparable store sales performance for Tim’s in three years and for Burger King in nearly seven years,” Mr. Schwartz said.

Burger King opened 15 net new units, and Tim Hortons opened 53 net new restaurants.

Growth at Burger King was driven by successful new products and promotions, including the Spicy BLT Whopper sandwich. The chain reported total revenues of $249.6 million, up 3.6% over the prior year, which included an unfavorable foreign exchange rate of approximately $14.5 million.

At Tim Hortons, continued day part expansion, combo meal penetration and recent product launches, including dark roast coffee and a crispy chicken club sandwich, led momentum for the Canadian coffee and donut chain. Total revenues at the chain declined 1.2% to $682.4 million compared to the prior year due to foreign exchange headwinds. Excluding the impact of the currency movements, total revenues grew 11% over the prior year.

Company shares were up more than 2% in mid-morning trading on the New York Stock Exchange on April 27 from the previous close of $41.57.