The bank, which employs 26,000 staff worldwide, is stepping up its lobbying as Labour and the Conservatives both promise tougher regulation of the financial services industry.
Chancellor Alistair Darling last month outlined a new council to oversee financial stability. Shadow chancellor George Osborne pledged to go further, saying the Tories would abolish the Financial Services Authority and give supervision powers to the Bank of England.
Nomura has turned to Fleishman-Hillard as it looks to engage decision-makers about the proposed changes to financial regulation. The agency was hired after a competitive pitch process. It is the first time Nomura has employed a retained agency to provide public affairs support.
Fleishman-Hillard will report to Nomura head of public affairs Julianne Lee. The account will be led by the agency's UK head of public affairs Nick Williams, working closely with colleagues in Brussels.
The decision to hire a public affairs agency follows Nomura's purchase of Lehman Brothers' European and Asian operations last year.
Nomura employees in London have grown from 1,500 last September to more than 4,000.
The bank is expected to move to new premises in the City of London in what would be the largest office deal in the Square Mile since 2005.