Len Blavatnik, a Russian-American oligarch, is to file a lawsuit today that accuses JP Morgan of mismanaging a $1 billion investment account owned by his industrial holding company, Access Industries, according to the New York Times.

In the lawsuit, Mr Blavatnik’s lawyers blame Ted Ufferfilge, a JP Morgan banker advising Access, for losing $98 million of the company’s money betting on risky subprime mortgage securities, the newspaper said.

Since the credit crunch started, the banking and wealth management industry has been braced for litigation connected to financial losses. In the case of the massive Ponzi scheme fraud of Bernard Madoff, the case has triggered a flurry of lawsuits, for example. As reported elsewhere at WealthBriefing today, Citi, for example, has rejected a lawsuit by former Singapore private banking client claiming that he lost more than $1 billion as a result of the bank providing inaccurate information and failing to execute some of his trades.

In the JP Morgan case, the lawsuit contends that Mr Ufferfilge told Access that its funds were being invested in conservative instruments - rather than the securities that wound up at the centre of the US mortgage crisis - according to a draft of the complaint prepared by the law firm Quinn Emanuel Urquhart Oliver & Hedges.

An Access spokesman told the NYT that JPMorgan bought the subprime securities for Access “at a time when the bank itself was unwinding its positions in similar investments.”

Mr Blavatnik has ownership stakes, through Access, in media and industrial companies, including the bankrupt chemicals giant LyondellBasell and the Russian oil company TNK-BP.

According to his lawsuit, Mr Blavatnik set up the JP Morgan account in late 2006, structuring it as an “enhanced cash management” fund that would earn a modest return while preserving accessible cash for various business operations.