Google's antitrust lawsuit against the US Department of Justice has revealed that Microsoft made an offer to sell Apple's Bing search engine in 2018.

In 2018, Microsoft made an offer to sell Apple's Bing search engine, according to a court filing earlier this month from Google. A document from Google's antitrust case against the US Department of Justice was made available to the public on Friday. 

The legal issue over whether Alphabet has a monopoly in web search advertising revolves around Google's significant agreements with Apple and Android phone makers to ensure the exclusivity of its search engine. In October 2021, a visual that was shown during the trial revealed that Google had paid over $26 billion to keep its search engine as the default. Google has been trying to show that competition is fair.

In the petition filed earlier this month, Google asserted that Microsoft had contacted Apple in 2009, 2013, 2015, 2016, 2018, and 2020 about making Bing the Safari browser's default internet browser. Apple rejected the request each time, citing issues with Bing's quality.

The Justice Department disclosed in a recently made public confidential document that Microsoft had made around $100 billion in Bing investments over a 20-year period. The Office and Windows software maker launched Bing in 2009 after launching search operations under the MSN and Windows Live brands.

With a 3% global market share, Bing is not as profitable as Google, which made $48 billion in Q4 from search and news advertising; Microsoft made $3.2 billion.