Last October, managers told an employee in Barclays (BARC) Plc’s trading unit to keep from clients a report showing the bank routed most of their dark pool orders to itself, according to the New York attorney general.

He refused, Eric Schneiderman said, and was fired the next day.

The state’s top law-enforcement official released the account, which he said he got from the former Barclays senior director, in a 30-page document that portrayed the London-based bank as bilking its own customers to expand its dark pool. Schneiderman cited a pattern of “fraud and deceit” starting in 2011 in which Barclays hoarded orders for stocks and assured investors they were protected from high-frequency firms while simultaneously aiding predatory tactics.

“The behavior described in this complaint would put a bank’s financial interest in marketing its dark pool and profiting by providing access to predatory high-speed traders ahead of the interests of investors,” Senator Carl Levin, the Michigan Democrat who leads the Permanent Subcommittee on Investigations, said in a statement. “Action is needed to end conflicts of interest in the U.S. stock market.”

David Fuller's view

The volumes on sordid practices weigh increasingly heavily on the reputations of our financial industries.