Just when it seemed that Alphabet (GOOG 0.60%) (GOOGL 0.58%) subsidiary Google was getting close to securing regulatory approval in the European Union for its proposed acquisition of wearables maker Fitbit (FIT), a new hurdle might be about to present itself. Japan is now reportedly looking to intensify antitrust scrutiny of major tech companies, including Google, Apple, Facebook, and Amazon.

Here's what investors need to know.

Exterior of Googleplex, Google's corporate headquaters

Image source: Google.

Japan could launch its own investigation

Reuters reports that Japan's Fair Trade Commission (FTC) will partner with regulatory counterparts in the U.S. and EU in order to bolster regulatory oversight of the behemoths. Scrutiny around giant tech companies and how they wield market power has been intensifying in recent years, and Japan is but the latest country to pile on the most valuable companies on Earth.

Japan's FTC chairman, Kazuyuki Furuya, suggested that his agency might investigate Google's proposed purchase of Fitbit. "If the size of any merger or business-tie up is big, we can launch an anti-monopoly investigation into the buyer's process of acquiring a start-up [like Fitbit]," Furuya told the outlet. "We're closely watching developments including in Europe."

It's unclear what threshold the transaction would need to exceed in order to trigger a probe, but the current offer on the table is for $2.1 billion, which values Fitbit at $7.35 per share in cash. Fitbit shares have consistently traded at a discount to that offer since it was initially announced in November 2019, reflecting investor skepticism that the deal will close.

The European Commission launched an investigation into the proposed acquisition to evaluate the potential impacts on competition, and the regulator recently extended the deadline to complete the probe into next year. Google has made various concessions and commitments -- most notably that it would not leverage Fitbit user data for advertising purposes -- that have reportedly satisfied regulators.

Furuya noted that the multinational tech companies typically use many of the same strategies across countries, making collaboration among regulators an important part of the process. The chairman vowed to take action regarding "any moves that hamper competition," and said that mergers are "an area I will push through aggressively."

Japan is not a particularly large market for Fitbit, but the country contributes somewhat more to Google's top line. The broader Asia-Pacific (APAC) region represented just 5% and 18% of Fitbit's and Google's revenue last quarter, respectively.

However, there's not much risk that Google and Fitbit can create a monopoly in the wearables market, since Fitbit commands just 3% market share globally across all wearables categories, according to IDC. Google is the dominant search engine in Japan, though, with 76% market share, StatCounter reports.