By Helen Bartholomew

LONDON, July 13 (Reuters) - Bruno Iksil, the JPMorgan Chase & Co trader known as the "London Whale", has left the bank, a person familiar with the situation said, in the wake of a trading scandal likely to have cost JPMorgan between $4 billion and $6 billion.

The Wall Street bank is due to report second-quarter earnings later on Friday and plans to disclose more about the bad derivatives bets its Chief Investment Office (CIO) made on portfolios of corporate bonds.

Iksil's departure had been widely expected after he became the focus of attention in the trading scandal, because of the huge positions he took in credit markets.

Achilles Macris, who headed CIO in Europe, and a third colleague, Martin Javier-Artajo, were also no longer listed in the company's internal employment database as of Thursday, the Wall Street Journal reported earlier on Friday.

Sources had told Reuters in May these two men were also on their way out after the debacle.

JPMorgan in London declined to comment.

The three staffers were still listed as "Active" in the register of individuals regulated by the Financial Services Authority, Britain's financial regulator.

It is a firm's duty to notify the FSA if an employee leaves the company, a spokesman for the watchdog said, but there could be a brief delay between the moment the FSA was notified and the database was updated, he said.

The Chief Investment Office was run by New York-based Ina Drew, who resigned in May.