The move comes at the end of a period of restructuring for Unisys, a NYSE-listed global tech firm with annual revenues of more than $5bn.
Brands2Life will seek to boost awareness of Unisys' offering at boardroom level, with a campaign targeting senior business and IT decision-makers.
The London agency will also promote Unisys to the trade press in the financial services, telecoms and public sectors.
The budget for the account has yet to be finalised, according to Brands2Life, but tech insiders have estimated the brief to be worth six figures.
Brands2Life was one of four agencies to pitch for Unisys' business in 2006, when FD replaced Cohn & Wolfe (PRWeek, 4 May 2006).
Band & Brown will remain on board as Unisys' retained agency for continental Europe (PRWeek, 10 August 2006).
Unisys' work includes 32 years as consultant for NASA's Langley Research Centre, developing the hardware and software behind the space programme's flight simulators and lunar modules.
Other Unisys clients include Spanish telecoms conglomerate Telefonica and Lloyds TSB. The company also worked with South Africa's Department of Home Affairs to develop its 43 million citizen ID cards.
Pennsylvania-based Unisys has weathered its fair share of controversies in the US, notably an FBI investigation into alleged security breaches during its work for the Department of Homeland Security.
The IT firm also made headlines for employing disgraced US lobbyist Jack Abramoff, although Unisys was not implicated in Abramoff's conspiracy trial.
Newly promoted board director and head of Brands2Life's interactive division Gareth Thomas will lead the account team, reporting to Unisys UKMEA PR manager Claire Daplyn. He is one of three
Brands2Life PROs promoted to board level this month. Directors Dan Chappell and Tony Smith have been appointed joint heads of its B2B practice.