The UK showed it won’t shy away from blocking the biggest global deals when it vetoed Microsoft Corp.’s $69 billion mega deal to buy Activision Blizzard Inc. in a surprise move.

Attention will now turn to the UK’s Competition and Markets Authority’s separate slate of deal probes into tech and digital markets, almost all of which could have a global impact.

The regulator typically choses to take about a dozen big mergers a year for an in-depth investigation. Here follows a list of the major deals on the watchdog’s plate.

Broadcom, VMware

Broadcom Inc.’s $61 billion deal to takeover cloud-computing company VMware Inc. is arguably the most important deal currently under investigation as regulators worldwide grapple with its impact on cloud computing hardware. The UK put it in an in-depth review last month after the firm did not offer any suggestions to allay the CMA’s concerns.

Viasat, Inmarsat

California-based Viasat Inc.’s $4 Billion plan to takeover London-based Inmarsat Group Holdings Ltd. to create the world’s biggest geostationary satellite company was provisionally cleared in the UK, following US approval, but it will give its final decision The CMA will come to a final decision by May 25.

Amazon, iRobot

Amazon.com Inc.’s $1.7 billion deal to buy robot vacuum firm iRobot Corp. is one of the latest deals to face scrutiny from the CMA. It said last week it had launched a merger probe into whether the deal could cause a substantial lessening of competition in the UK. A decision on whether it will go to an in-depth probe won’t come until June. It’s the latest in a list of investigations the e-commerce giant is facing in the UK, with its marketplace and cloud services businesses currently being looked at.

--With assistance from Katharine Gemmell.