JPMorgan, acquiring rival investment bank Bear Stearns
Meanwhile, a JPMorgan spokeswoman told CNBC that the firm would cut some existing JPMorgan jobs to help offset the new staff joining from Bear Stearns.
"We are not growing our workforce by 6,000 jobs," she said. The spokeswoman put JPMorgan's net increase at about 3,000 positions.
Earlier on Monday Chief Executive James Dimon said about three-fourths of people decisions have been completed so far, with 40 percent offered jobs..
The remaining roughly 3,500 employees will learn their fates in the next two weeks. Those staffers, mostly in technology and operations, and will likely see a lower percentage of job offers, the source said.
The merger is expected to be completed June 1.
The fate of Bear's bankers and traders have been hanging in the balance since March 16, when the New York bank was forced into a merger with the bigger, stronger JPMorgan.
For weeks, JPMorgan officials denied they knew how many layoffs would result from the merger.
There has been widespread speculation that about half of Bear's employees would be laid off.
JPMorgan is under pressure to keep costs and combined headcount under control as the financial market slump continues to depress business.
With Wall Street banks firing tens of thousands of employees, JPMorgan expects to cut from its own staff to make room for Bear Stearns employees deemed superior, the source said.
SEC Charges Coming?
In a separate matter, JPMorgan said on Monday that it received a notice from federal regulators indicating that one of its units may face an enforcement action related to "the bidding of various financial instruments associated with municipal securities.''
Last month, Bear Stearns also got a notice from the U.S. Securities and Exchange Commission indicating possible civil charges, stemming from anti-competitive activity relating to bidding for municipal securities.