By Terry Baynes

Nov 16 (Reuters) - A representative for the victims of Allen Stanford's estimated $7 billion Ponzi scheme is suing two law firms he says helped the now-convicted swindler perpetrate his fraud.

The court-appointed receiver, the Official Stanford Investors Committee and individual investors sued Greenberg Traurig and Hunton & Williams on Thursday, claiming that lawyer Carlos Loumiet, who worked for both firms, was instrumental in Stanford's scheme.

"Stanford could not have perpetrated this global mass fraud on his own. He needed corrupt regulators in his chosen offshore jurisdiction of Antigua, shady accountants, and skilled and complicit lawyers to help him," the complaint said.

The lawsuit said Stanford relied on Loumiet, a Miami international banking lawyer who was Stanford Financial Group's outside counsel from 1988 to 2009. For the first 13 of those years, Loumiet was a partner at Greenberg Traurig before moving to Hunton & Williams in 2001.

Loumiet helped Stanford set up a safe haven in Antigua and established U.S. offices that sold certificates of deposit to Latin American investors, the complaint said. He also helped Stanford invest his profits in Caribbean real estate, venture capital investments and an unsuccessful movie project, it said.

"Loumiet counseled Stanford for over twenty years on how to evade U.S. laws and regulations while still operating primarily from U.S. soil," the suit said. He also recommended fellow lawyer Yolanda Suarez, who went on to become the general counsel of Stanford Financial Group. Suarez, but not Loumiet, is named as a defendant in the suit.

A lawyer for Yolanda Suarez did not immediately respond to requests for comment.

Loumiet said in an emailed statement that he has never helped any client commit any wrongdoing nor represented anyone he knew was engaged in illegal activity.

"After years of investigations by the federal government and months of trials involving Allen Stanford and his co-defendants, I have not been implicated in any wrongdoing," he said.

The law firms also denied having any responsibility for Stanford's fraud.

Hunton & Williams called the suit "an overreach by Stanford Financial Group's understandably frustrated investors attempting to recoup their unfortunate losses."

Greenberg Traurig said its work for Stanford occurred prior to 2001, three years before the sale of the CDs at the center of the suit.

"This is merely plaintiffs' newest attempt to pry open a deep pocket," Greenberg Traurig's lawyer Jim Cowles said in an emailed statement, noting 63 other individual lawsuits and 15 pending class action claims, including against other large law firms and accounting firms.

Similar suits against law firms Proskauer Rose and Chadbourne & Parke and insurance broker Willis Group Holdings Ltd are currently on appeal before the U.S. Supreme Court. The firms claim that the class actions brought under state law are barred by federal securities law. They say investors should not be able to go after deep-pocketed third parties only tangentially related to the fraud. The 5th U.S. Circuit Court of Appeals in New Orleans had allowed the cases to proceed in March.

A lawyer for the investors, Edward Snyder of Castillo Snyder, said in an email that Loumiet "worked hand in hand" with Stanford and others to design the basic architecture of the Ponzi scheme. Snyder also represents investors in the lawsuits against Proskauer and Chadbourne.

The latest suit alleges violations of the Texas Securities Act and claims over $1.8 billion in losses to the investor committee and at least $7 billion to the entire investor class, a s well as punitive damages to be determined at trial.

Stanford was convicted in March of 13 charges including fraud and conspiracy for selling certificates of deposit from his bank in Antigua to thousands of investors in the United States and Latin America. He had already spent some of those proceeds on yachts, girlfriends, sponsorship of a cricket tournament and other accoutrements of a high-rolling life.

Stanford was sentenced to 110 years in prison in June.

The case is Janvey et al v. Greenberg Traurig et al, U.S. District Court, Northern District of Texas, No. 12-4641.

For the investor class: Edward Snyder and Jesse Castillo of Castillo Snyder.

For the Stanford Investors Committee: Edward Valdespino of Strasburger & Price; Peter Morgenstern of Butzel Long.

For the receiver, Ralph Janvey: Nicholas Foley and Douglas Buncher of Neligan Foley.

For Greenberg Traurig: Jim Cowles of Cowles & Thompson.

For Loumiet and Hunton & Williams: April Otterberg and Jeffrey Colman of Jenner & Block.

For Suarez: Not immediately available.

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