* Gregg Mulholland arrested during Phoenix layover
* Cynk market cap soared past $6 billion without explanation (Adds allegations, Cynk background, case citations, byline)
By Jonathan Stempel
NEW YORK, June 23 (Reuters) - A dual U.S. and Canadian citizen has been criminally charged with running a stock manipulation fraud that generated $300 million of illegal profit, and included a pump-and-dump scheme that caused the market value of little-known Cynk Technology Corp to rocket past $6 billion.
Gregg Mulholland, 45, is charged with securities fraud and money laundering conspiracies following his arrest on Tuesday at Phoenix International Airport during a layover of his flight to Mexico from Canada.
Mulholland's arrest and criminal charges were announced by Acting U.S. Attorney Kelly Currie in Brooklyn, New York.
The U.S. Securities and Exchange Commission filed a related civil lawsuit against Mulholland, who authorities said lives in Vancouver, British Columbia, and San Juan Capistrano, California.
It was unclear whether Mulholland has hired a lawyer.
Last July, U.S. authorities suspended trading in Cynk, a development stage company with no revenue or assets, after its share price soared without explanation to $21.95 from 6 cents in less than a month.
That surge, which followed a month when no Cynk shares were traded at all, briefly gave the company a market value higher than three dozen members of the Standard & Poor's 500.
Using wiretaps to build their case, authorities believe Mulholland, who sometimes went by the names "Stamps" and "Charlie Wolf," was behind that volatility, having previously amassed tens of millions of Cynk shares to conduct a "classic" pump and dump scheme.
Prosecutors accused Mulholland of also manipulating the shares of numerous other public U.S. companies, and laundering the profit through at least five offshore law firms to avoid Internal Revenue Service reporting requirements.
They said Mulholland was also the "secret" owner of Legacy Global Markets SA, a Panama- and Belize-based broker-dealer and investment manager indicted last September in Brooklyn over a separate alleged $500 million fraud scheme.
"Mulholland used an elaborate offshore corporate structure built on lies and deceit," and fled the United States after the earlier indictment, Currie said in a statement.
The defendant is expected to appear on Wednesday before a federal judge in Phoenix. Mulholland faces up to 20 years in prison if convicted.
The cases are U.S. v. Mulholland, U.S. District Court, Eastern District of New York, No. 15-mj-00562; and SEC v. Mulholland in the same court, No. 15-03668. (Reporting by Jonathan Stempel in New York; Editing by Andre Grenon)