The U.S. Securities and Exchange Commission moved decisively into the Aequitas Capital Management scandal Thursday, suing the Lake Oswego company and three top executives for allegedly running a $350 million Ponzi scheme.

The SEC claims Aequitas defrauded more than 1,500 investors into believing they were making health care, education and transportation-related investments, when their money was really being used in a last-ditch effort to save the firm.

The commission has asked the court to appoint a receiver to take control of Aequitas. It also removed Aequitas chief executive Bob Jesenik and his longtime partner, Brian Oliver, from positions at the company and sought to ban them from the securities industry.

Jesenik, Oliver and Scott Gillis, former Aequitas chief financial officer, were named defendants in the complaint.

Filed late Thursday in U.S. District Court in Portland, the suit alleges that since 2014, Aequitas has used much of the new money it raised from investors to fund operating expenses and, increasingly, to pay off existing investors.

"By at least July 2014, Jesenik and Oliver knew that redemptions and interest payments to prior investors were being paid primarily from new investor money in a Ponzi-like fashion, and that very little investor money was being used to purchase trade receivables," the SEC alleges.

Jesenik said the SEC rushed to judgment.

In a written statement issued by his lawyer, Jesenik said Aequitas brought on a consulting company called FTI last month. Thursday, in an effort to protect investors' interests, he said the SEC agreed to ask a federal judge to retain FTI as a receiver in the case.

"However, I'm disappointed that the SEC has also chosen to rush to judgment about the company's management and make sweeping allegations without the benefit of a thorough investigation," Jesenik said. "I look forward to addressing these claims in court."

Oliver too disputed the SEC's claims. ""Brian has not done anything wrong and we are deeply disappointed that the SEC would make such serious allegations without even speaking to him," said Oliver's lawyer Jahan Raissi.

After reading the complaint, veteran Portland securities lawyer Bob Banks said it's a wonder Aequitas executives and its allies "that peddled these junk notes into 2016 can sleep at night."

"I've listened to panicked Aequitas investors for the last two weeks, some of them in tears," said Banks, who is representing some of those investors. "Some have lost their children's college funds, some don't know how they will pay for medical treatments that they need. There are people in their 80s and 90s who turned over a lifetime of savings to Aequitas."

As first reported by The Oregonian and OregonLive, Aequitas was hurt badly when its deal to buy hundreds of millions of dollars worth of student loans from controversial for-profit college Corinthian Colleges fell apart in January 2014. Though the loans were deemed predatory and illegal by a federal judge, it was Aequitas largest source of revenue. The company continued to try and collect the debt from former Corinthian students long after Corinthian went bankrupt.

The SEC claimed in its lawsuit that Corinthian accounted for 75 percent of Aequitas debt-buying business. Aequitas insisted to the bitter end that losing Corinthian had an "immaterial" impact on the company.

As Aequitas' position grew weaker, it became more desperate to raise investor cash. By late 2014, it offered to pay investors 15 percent interest if they would commit their money for a full year, an extraordinary rate of return in today's low-interest environment.

The Aequitas scandal could spread well beyond Oregon. The company convinced independent investment advisers from Puget Sound to Long Island to peddle its private note investments. Aequitas paid many of them 2 percent commissions for every dollar they steered into its private notes.

Investors across the country, some of whom are convinced they were misled, have lawyered up and are considering whether to sue Aequitas, their individual investment advisers or both.

The company laid off most of its employees in February.

In all investors have about $600 million in Aequitas private notes and in various Aequitas investment funds. It remains unclear how much they will recover.

-- Jeff Manning

503-294-7606, jmanning@oregonian.com