The entire London staff of JPMorgan Chase & Co.'s chiefinvestment office is at risk of dismissal as a $2 billion tradingloss prompts the first executive departures as soon as this week, aperson familiar with the situation said.

Ina Drew, who oversees the unit, may resign as soon as thisweek, according to another person, who requested anonymity becausethe deliberations are private. Joseph Evangelisti, a bankspokesman, said Drew would have no comment. While the firm isexamining whether anyone in the unit, which employs a few dozenpeople in London, sought to hide risks, there isn't yet evidencethat's the case, one of the people said.

Chief Executive Jamie Dimon, 56, announced the loss May 10,assailing his firm's handling of trading in synthetic creditsecurities as “flawed, complex, poorly reviewed, poorly executedand poorly monitored.” Initially, he resisted accepting Drew'sresignation, the person said. The incident has given ammunition toproponents of stricter bank regulations.