UPDATE 2-After Credit Suisse plea deal, top U.S. tax enforcer steps down
* Kathryn Keneally spent two years at Justice Department
* Credit Suisse was largest bank in decades to plead guilty to aiding tax evasion (Adds details on Keneally's tenure and Swiss bank settlement, lawyer comment)
WASHINGTON May 27 (Reuters) - The U.S. Justice Department's top tax enforcement official will leave the agency next week, after securing a $2.6 billion settlement and guilty plea from Credit Suisse over charges the Swiss bank helped Americans evade U.S. taxes.
Kathryn Keneally's last day will be June 5, the Justice Department said on Tuesday.
"As a result of her determined efforts ... the Tax Division has secured historic gains in our fight to protect the American people from tax fraud and financial misconduct," Attorney General Eric Holder said.
Keneally, 56, said in a statement that she is looking forward to returning to her home in New York.
Keneally started in March 2012, filling a position that was without a confirmed nominee for the first three years of Barack Obama's presidency.
Credit Suisse on May 19 became the largest bank in decades to plead guilty to a criminal charge after facing accusations that it helped American clients conceal assets in secret accounts that were not disclosed to U.S. tax authorities.
Keneally played an essential role in negotiating the Credit Suisse settlement, officials have said, and first alerted the bank last October that she was prepared to recommend prosecution.
More than a dozen other Swiss banks remain under investigation for similar practices.
Keneally was respected for aggressively pursuing offshore tax evasion, said Jay Nanavati, a former Justice Department tax lawyer now with Baker & Hostetler LLP. With her departure, it remains to be seen how hard the Justice Department will continue to go after new banks suspected of helping Americans hide assets, he added.
Keneally is leaving amid the Justice Department's first-ever settlement program for Swiss banks that allegedly helped Americans dodge taxes.
More than 100 Swiss banks have agreed to participate in the program, announced last August, that allows them to avoid or defer U.S. criminal prosecution if they pay penalties and disclose account information about U.S. customers.
These banks have until June 30 to turn over to the Justice Department certain information about U.S. customer accounts. (Reporting by Aruna Viswanatha; Editing by Doina Chiacu, Howard Goller and Andrew Hay)