The blockbuster merger is facing close scrutiny from regulators in the U.S., Europe and elsewhere. Microsoft, maker of the Xbox game console, faces resistance from Sony, which makes the competing PlayStation console and has raised concerns with antitrust watchdogs about losing access to what it calls a “must-have” game title.

Phil Spencer, the head of Xbox, tweeted that Microsoft “entered into a 10-year commitment” to bring Call of Duty to Nintendo.

Microsoft President Brad Smith tweeted his thanks to Nintendo, which makes the Switch game console, saying the same offer was available for Sony.

“Any day @Sony wants to sit down and talk, we’ll be happy to hammer out a 10-year deal for PlayStation as well,” he said.

Smith said the agreement would bring Call of Duty to more gamers and more platforms, and “that’s good for competition and good for consumers.”

Sony’s European press office didn’t respond to a request for comment. Adding to the pressure on Sony, Microsoft also said Wednesday it has committed to keeping Call of Duty on the platform Steam, a digital marketplace for PC games, in an agreement with Steam’s operator Valve.

In an op-ed for The Wall Street Journal this week, Smith raised concerns about the possibility that the Federal Trade Commission could take Microsoft to court to stop the deal. Antitrust watchdogs in both Britain and the European Union also are investigating the transaction over concerns it would distort competition.

At the heart of the dispute is control over future releases of Activision Blizzard’s most popular games, especially Call of Duty, a first-person military shooter franchise. Activision reported last month that the latest installment, Call of Duty: Modern Warfare 2, had earned more than $1 billion in sales since its Oct. 28 launch.