Will Burger King get burned by Canada move?

Burger King is ruling a larger fast-food kingdom — and having to defend its move on social media.

The U.S.-based restaurant chain made it official Tuesday announcing that it agreed to merge with the Canada-based Tim Hortons restaurant chain. The deal, valued at about $11 billion, will create the world's third-largest fast-food company, with about $23 billion in annual sales and more than 18,000 restaurants in 100 countries.

The new global company will be headquartered in Canada, but each brand will be managed independently, with Burger King retaining its U.S. offices in Miami, the two companies said in a joint statement.

With a new base in Canada, the Burger King merger quickly was lumped into the growing public outcry over tax inversions, which allow U.S. companies to lower their tax bills by reincorporating in a country with lower corporate tax rates through a merger with a foreign firm.

By midday several thousand comments had flooded Burger King's Facebook page. On Twitter, #TimHortons was a trending topic with #BoycottBurgerKing and similar tweets numbering in the hundreds.

Burger King CEO Daniel Schwartz, who will become group CEO of the new company and handle day-to-day management, said that "the company is going to continue to be managed out of our Miami office." "We are going to continue to pay U.S. taxes as we have been doing," he said in a conference call with media after the deal's announcement.

The deal was not about taxes, Schwartz said, noting that the corporate tax rate paid by Tim Hortons in Canada is in the mid-20s percentage-wise and Burger King's "blended" tax rate it pays globally, including U.S. taxes, is also in the mid-20s. "So when we look at the combined company we don't expect there to be meaningful lower or higher tax rates than we had before," he said.

Instead, he said, "What is going to add value and drive growth for the long run is ... more restaurants around the world and growing sales and profits."

Tax and business planning attorney Paul Gilman of Chicago-based law firm Aronberg Goldgehn Davis & Garmisa expects that Burger King's U.S. tax rate won't change much "because they derive most of their income from franchisees, and (those in the U.S.) are still going to be subject to tax," he said.

Burger King has "to get out in front" of any possible public boycott. "All of a sudden people on my Twitter and Facebook feeds are saying 'Boycott Burger King,' but don't boycott (them) because these are small businesses that need the revenue, and Burger King is going to pay U.S. tax on those. They can't shift those dollars out of the country."

Regardless, Burger King may have a public affairs brouhaha cooking. Several members of Congress, including Sen. Dick Durbin, D-Ill., decried Burger King's Canadian business move. In recent months, as more companies have used inversions, President Obama and Congress have publicly criticized the moves because they cut into U.S. tax revenue.

"Burger King's decision to abandon the United States means consumers should turn to Wendy's Old Fashioned Hamburgers or White Castle sliders," said Sen. Sherrod Brown, D-Ohio. Wendy's and White Castle are based in Ohio.

For the two companies, the merger made good business sense, says Matt Porzio, vice president of strategy and product marketing at Intralinks, which provides online deal-sourcing tools for mergers and acquisitions. "These big companies have got to grow," he said, "and the best way to grow right now is to acquire and grow inorganically. It just so happens Tim Hortons is in Canada, which might have a tax benefit to them. But if Dunkin' Donuts brand group was in their wheelhouse ... they probably would have considered that."

Warren Buffett's investment firm, Berkshire Hathaway, committed $3 billion of preferred equity financing for the deal, but will not have any participation in the management and operation of the business, the companies said.

Tim Hortons' stock surged 8.5% to close at $81.05, and Burger King's stock fell 4.3% to $31.00.

Tim Hortons, with about 850 outlets in the U.S., can gain reach globally and here with Burger King's help. And Burger King might get some advice on breakfast strategies to counter new products from Taco Bell and Subway.

By combining the two companies, "We are creating a global (quick-service restaurant) powerhouse," said Alex Behring, executive chairman of Burger King and managing partner of 3G Capital, the majority owner of Burger King.

Behring will become executive chairman and director of the new company, and Tim Hortons CEO Marc Caira, as vice chairman and a director, will handle overall group strategy and global business development, the companies said.

The new company is expected to trade on the New York Stock Exchange and the Toronto Stock Exchange.

Under the deal, Burger King will pay $65.50 Canadian ($59.74) in cash and 0.8025 common shares of the new company for each Tim Hortons share. This represents total value per Tim Hortons share of $94.05 Canadian ($85.79), based on Burger King's Monday closing stock price. Alternatively, Tim Hortons shareholders may choose either all cash or all stock in the new company.

Contributing: The Associated Press