It is the first time the country has issued such an order to a global technology giant, Japanese media reported, and follows similar moves in Europe and the United States.

"We have concluded that Google LLC's conduct threatens to impede fair competition," Saiko Nakajima of the Japan Fair Trade Commission (JFTC) told reporters on Tuesday.

The problem is "related to the implementation of search functions for Android smartphones, in violation of the antitrust law", she said.

The JFTC accuses Google of imposing binding conditions on Android smartphone manufacturers in Japan since at least July 2020.

Specifically, it says Google made sure its online app store Google Play would be installed as part of a package with its web-browser search app Chrome.

Google Play is so widely used that without it, "Android devices are basically unsellable", a government source told AFP in December.

No financial penalties were announced Tuesday, but Nakajima said the order would increase the options available to smartphone makers.

"This will encourage competition and benefit" society, she said.

Google Japan said it was "disappointed" by the JFTC's findings.

"(Our) agreements with Japanese partners help to promote competition and have undeniably boosted their ability to invest in product innovations which deliver more choice for consumers," it said in a statement.

"We will review the order thoroughly to determine our next steps."

The US government asked a judge in November to order the dismantling of Google by selling its widely used Chrome browser, in a major antitrust crackdown on the company.

And the European Commission said in 2023 that Google should sell parts of its business and could face a fine of up to 10 percent of its global revenue if it fails to comply.

In Japan, the JFTC conducted an on-site inspection of Amazon's Japanese subsidiary in Tokyo last year, accusing it of abusing its industry dominance to drive down prices.

Amazon Japan used its coveted "buy box" -- a prominent spot on its website -- against sellers, pressuring them into lowering prices to give it a competitive edge over rival e-commerce sites, the JFTC said.