Apple and other smartphone makers turned down revenue-sharing agreements that would have helped Microsoft's Bing search engine and instead kept Google as the default search engine, a Microsoft executive testified on Thursday.

Jonathan Tinter, a Microsoft vice president whose job has been to help Bing grow, testified at the US Justice Department's antitrust trial against Alphabet's Google in US District Court in Washington.

DOJ accuses Google of paying $10 billion annually to wireless carriers and smartphone makers to ensure that Google search is the default on their devices. The government argues Google has abused its monopoly in search and some aspects of search advertising.

Tinter said that Bing has struggled to win default status on smartphones sold in the United States and that this smaller scale translated into poorer quality search.

Under Justice Department questioning, Tinter testified that Bing was not the default installed in any Android or Apple smartphone sold in the U.S. in the past decade, even though Microsoft would at times offer to give more than 100% of revenue - or more - to its partner.

A lawyer for Google pressed Tinter on whether it was money or poor quality which prevented Bing from ousting Google as the default search engine on smartphones and other devices.

He pointed to an analysis done by Keystone Strategies from 2010 which found that people who discover Bing use it only for a very short time.

"The number of Bing users that stay is in single digits," he said. "More than half of new users have only one active day on Bing mobile before leaving," the attorney said. Tinter declined to agree.