MANHATTAN (CN) - More than 20 influential Chevron shareholders, including the New York comptroller and Oxfam America, signed a letter urging Chevron to enter settlement negotiations with a group of indigenous Ecuadorean who won an $18 billion environmental lawsuit against the oil giant earlier this year. One signer, Trillium Asset Management, has even asked  (.pdf) the Securities and Exchange Commission to investigate Chevron for allegedly failing to adequately disclose the risks the judgment poses to the oil company's reputation and finances. A spokeswoman for the Ecuadoreans suing Chevron estimated that more than 100 activists swarmed Chevron's shareholder meeting on Wednesday in San Ramon, Calif., to protest. She added that a tribal leader from Ecuador's rainforest, Humberto Piaguaje, and dozens of environmental activists confronted Chevron CEO John Watson inside the meeting. Chevron spokesman Kent Robertson dismissed the shareholder pressure in an email, saying the company would fight the "fraudulent" award, not settle it. In 2009, a different company spokesman, Donald Campbell, outlined the oil giant's legal strategy: "We're going to fight this until hell freezes over. And then we'll fight it out on the ice." Trillium's lawyer Sanford Lewis told Courthouse News that this sort of talk makes shareholders uneasy. "Do they want to go to hell with Chevron?" Lewis asked. As the decades-long trial started winding down, Chevron claimed that the Ecuadoreans, along with their attorneys and consultants, defrauded the Ecuadorean courts to extort a multibillion-dollar settlement. Earlier this year, Chevron accused them in Manhattan of violating federal anti-racketeering law. They also appealed the verdict in Lago Agrio and sued the government of Ecuador in The Hague. Concurrent with Wednesday's shareholder meeting, dozens of investors released a statement telling Chevron to rethink its legal approach. "In failing to negotiate a reasonable settlement prior to the Ecuadorian court's ruling against the company, we believe that Chevron displayed poor judgment that has led investors to question whether our Company's leadership can properly manage the array of environmental challenges and risks that it faces," the letter states. Some of the signatories include Oxfam America, Catholic Health Partners, International Brotherhood of Teamsters General Fund, Mercy Investment Services, Pinnacle Investment Advisors, Unitarian Universalist Association and American Federation of Labor and Congress of Industrial Organizations. They claim to collectively represent $156 billion in Chevron assets under management. Robertson, the Chevron spokesman, said that they are urging the wrong approach. "Chevron does not believe that settling a fraudulent lawsuit is in the best interests of our stockholders," he said. "We intend to hold accountable all those who have knowingly participated in this unlawful scheme to defraud Chevron and its stockholders." One of the signers, Trillium Asset Management, took shareholder activism a step further by asking the SEC to investigate Chevron. In its May 19 letter, Trillium told the SEC that, although the Ecuadoreans' lawsuit stretched for 18 years, Chevron waited until 2009 to disclose possible liabilities. Chevron's most recent annual report disclosed but downplayed the Feb. 14 verdict, Trillium wrote. "Management does not believe an estimate of a reasonably possible loss (or a range of loss) can be made in this case," Chevron's 2010 annual report stated. "Moreover, the highly uncertain legal environment surrounding the case provides no basis for management to estimate a reasonably possible loss (or a range of loss)." (Parentheses in original.) Just over a week before Chevron's report was published, its comptroller Rex Mitchell warned of "irreparable injury to Chevron's business reputation and business relationships" without a preliminary injunction. Lewis, one of Trillium's lawyers, said that he has initiated SEC inquiries "a couple of times a year" for more than a decade for clients ranging from nongovernmental organizations to a large pension fund. He said that one of his earliest successes came when a union within the AFL-CIO initiated a 1997 boycott against Crown Petroleum over a labor dispute. "They were actually reporting in their SEC filings that their sales were down due to competitive effect," Lewis said. "When we looked at why the sales were down, they started to drop right at the same that the boycott was an issue. And so one of these letters was filed with the SEC, and pretty soon the company turned around and revised their SEC filings." Lewis added that most companies "self-correct" when faced with SEC investigation, and this brand of shareholder activism "helps to clean up the disclosure market." Chevron's spokesman insists the company has been forthcoming. "Chevron has made information about the litigation available on multiple websites, we have communicated directly with stockholders on the issue, and our view that the judgment in Ecuador is illegitimate and unenforceable has been widely covered by major media outlets," Robertson said. He added that the Trillium cited a report in its SEC inquiry that was commissioned by two defendants in the racketeering suit: Amazon Watch and the Rainforest Action Network. "Trillium, for its part, has a long history of trying to mislead Chevron stockholders," Robertson said. Lewis replied that these organizations had no editorial control over the report, and he said Chevron paints with "a really broad brush, accusing all kind of people of this conspiracy." With a settlement unlikely, Chevron hopes a Manhattan federal judge will declare the Ecuadorean judgment unenforceable after a November trial. The Ecuadoreans, who deny the court's jurisdiction, say they will pursue collection efforts outside America after their country's provincial court upholds the award.