A US federal judge in New York, Denise Cote, has revived a lawsuit alleging that Lyondell intentionally cheated creditors out of $6.3 billion when it underwent a 2007 leveraged buyout by Access Industries before going bankrupt less than a year later, the news agency Reuters reports. Cote said the federal bankruptcy judge erred in dismissing a bid by Edward Weisfelner, a trustee representing Lyondell’s unsecured creditors, to recover the money from shareholders who pocketed roughly $12.5 billion.

In December 2007, US-based Lyondell merged with Basell, a former joint venture of BASF and Shell based in the Netherlands that had been acquired by Access, the investment vehicle of Russian-born billionaire Len Blavatnik. The merged company went bankrupt in January 2009 as due to the high level of debt it was carrying it could not cope with slumping demand at the height of the worldwide financial crisis.

US and European creditors of LyondellBasell and its predecessor companies charged at the time that the backers of the merger chose to ignore well-known risks, such as the cyclical downturn that began in 2008. "We are extremely encouraged," Weisfelner said in an interview with Reuters, adding: “There is a very good chance there will be recompense for creditors who were injured and have been waiting years."

In the original suit Weisfelner had accused Lyondell's former chairman and chief executive, Dan Smith, of pushing for a buyout he knew would overburden the company even as it benefited shareholders. Smith himself allegedly netted more than $100 million in the deal. According to Reuters, litigation over the buyout persists even though LyondellBasell emerged from bankruptcy in April 2010.

In November 2015, US bankruptcy Judge, Robert Gerber, who has since left the bench, rejected the trustee's intentional fraudulent transfer claim, saying he found no proof that Smith controlled his board on the buyout vote, or that a “critical mass” of directors intended to defraud creditors. Cote, however, said Gerber had misinterpreted the law.

The case has been forwarded to US bankruptcy judge, Martin Glenn, who now oversees litigation related to leveraged buyouts.