Mikhail Zadornov, 42, said he would resign Friday during a session of the lower chamber of parliament, the State Duma.
"The decision will be made at a plenary session tomorrow," Zadornov, who was finance minister in 1997-1999, told a news conference.
A member of the liberal Yabloko party, Zadornov was elected to the Duma four times.
The board of Vneshtorgbank Retail Services, part of the Vneshtorgbank group, approved Zadornov as bank president and board chairman on June 10. This is a new bank, which will start functioning on August 1 under the name Vneshtorgbank 24.
Zadornov said the bank name Vneshtorgbank Retail Services had been registered with the Federal Tax Service on July 1. The new lending organization was transformed from Guta Bank, 85% of whose shares were acquired by the VTB group last summer.
Zadornov said the objective was to establish the second largest retail bank in Russia, something that would take five years. "This is a five-year project, and establishing the bank itself will take at least three years," the former minister added.
He said he would dedicate 95% of his working time to the bank and would engage in political activities if he had any time left.