By Foo Yun Chee

BRUSSELS Microsoft President Brad Smith will on Tuesday seek to convince EU antitrust regulators at a closed hearing that the U.S. software giant's $69 billion bid for "Call of Duty" maker Activision Blizzard will boost competition.

Smith will lead a delegation of 18 senior executives, including Microsoft Gaming Chief Executive Officer Phil Spencer, while Activision will be represented by its CEO Robert Kotick according to a European Commission document seen by Reuters.

The hearing will allow Xbox maker Microsoft to gauge the mood among senior EU and national competition officials and Commission lawyers ahead of the submission of remedies to address antitrust concerns.

Microsoft announced the acquisition in January last year to take on leaders Tencent and Sony, but has run into regulatory headwinds in Europe, Britain and the United States.

Sony, which wants the deal to be blocked, is sending its gaming chief Jim Ryan.

Alphabet's Google and chip designer and computing firm Nvidia Corp, which has a gaming business, will also be taking part in the hearing, the EU document showed.

"The European Commission asked for our views in the course of their inquiries into this issue. We will continue to cooperate in any processes, when requested, to ensure all views are considered," a Google spokesperson said.

Nvidia declined to comment. The European Games Developer Federation (EGDF), which has said the deal will allow Microsoft to challenge Apple, Google and Tencent, is one of the participants.

Video game distributor Valve, video game publisher Electronic Arts and the German competition watchdog and its peers in Belgium, the Czech Republic, Finland, France, Italy, Portugal, Spain and Sweden will also be taking part in the event.

(Reporting by Foo Yun Chee; Editing by Chris Reese)