In the run-up to that conference, Ms. Slaughter and New America’s lead fund-raiser in emails to Mr. Lynn indicated that Google was concerned that its positions were not going to be represented, and that it was not given advanced notice of the event.

“We are in the process of trying to expand our relationship with Google on some absolutely key points,” Ms. Slaughter wrote in an email to Mr. Lynn, urging him to “just THINK about how you are imperiling funding for others.”

Mr. Lynn is now starting a stand-alone nonprofit with the same team to continue Open Markets’ work. The new group, which does not yet have a name, has funding commitments, though clearly is not expecting money from Google. It has launched a website called Citizens Against Monopoly that accuses Google of “trying to censor journalists and researchers who fight dangerous monopolies.” The site vows, “We are going to make sure Google doesn’t get away with this.”

After initially eschewing Washington public policy debates, which were seen in Silicon Valley as pay-to-play politics, Google has developed an influence operation that is arguably more muscular and sophisticated than that of any other American company. It spent $9.5 million on lobbying through the first half of this year — more than almost any other company. It helped organize conferences at which key regulators overseeing investigations into the company were presented with pro-Google arguments, sometimes without disclosure of Google’s role.

Among the most effective — if little examined — tools in Google’s public policy toolbox has been its funding of nonprofit groups from across the political spectrum. This year, it has donated to 170 such groups, according to Google’s voluntary disclosures on its website. While Google does not indicate how much cash was donated, the number of beneficiaries has grown exponentially since it started disclosing its donations in 2010, when it gave to 45 groups.

Some tech lobbyists, think tank officials and scholars argue that the efforts help explain why Google has mostly avoided damaging regulatory and enforcement decisions in the United States of the sort levied by the European Union in late June.

But Google’s Washington alliances could be tested in the coming months. Google emerged as a flash point in the latest skirmish of the culture wars this month after one of its male engineers posted a critique of the company’s efforts to diversify. And its data collection continues fueling questions about its commitment to privacy.