Brevan Howard called in the agency without a competitive pitch.
Peregrine has been brought on board to handle media relations for the group and for Brevan Howard's London Stock Exchange-listed vehicles BH Macro and BH Global.
BH Macro was launched 18 months ago and has $1.5bn assets under management. BH Global was launched this May and has $1bn assets under management.
Following the win, Peregrine Communications now handles all the major closed-ended listed funds on the London Stock Exchange, and all the FTSE 250 hedge funds.
Founder Anthony Payne said the win was 'a major boost for (the agency's) strategy of focusing on the alternative financial sector'.
'The main focus of the comms strategy will be to develop awareness of the Brevan Howard brand via its flagship funds BH Global and BH Macro, and communicate to investors how the strategies work in both good and bad market conditions,' he added.
Peregrine's brief is to reach institutional investors through the financial press.
The account will be headed up by Payne.
Brevan Howard is one of the world's biggest hedge fund groups, with $25bn assets under management. The fund specialises in global macro investing, such as betting on interest rates and currencies.
It was founded by Alan Howard and a team from Credit Suisse in 2002, and now has 10 offices worldwide. The firm has a total staff of 339 employees, most of which are based in London.
Peregrine has been brought in to replace incumbent financial PR shop Maitland, which has been handling Brevan Howard's PR support for the past two years.
Last month Peregrine also added Harbour Capital, a London-based hedge fund infrastructure management platform, to its roster of hedge fund clients.
The agency was set up by Payne in 2003 following his departure as MD of Hill & Knowlton's financial division.
Earlier this year Europe's largest hedge fund, GLG Partners, took on Finsbury as it dealt with the exit of its largest fund manager, Greg Coffey (PRWeek, 8 May).
Coffey, who controlled £3.5bn of GLG's funds under management, took on his own support for his high-profile exit, turning to Tulchan.
HOW I SEE IT - CAROLINE CAMPBELL, MD, THE EDINBURGH PR COMPANY
The hedge fund sector is not known for its openness and does not publish much information on portfolio positions and strategies. Peregrine's job will be as much about what it doesn't say as it is about getting key messages across to a niche group of knowledgeable investors. In a volatile marketplace, with many hedge funds in distress and regulatory issues at the forefront, market sentiment is inevitably low. One of Peregrine's challenges is perhaps to be seen as adopting an open approach, keeping investors informed yet avoiding any specifics.