This week, it emerged that BAE had completed a review of agency support for government affairs activity, overseen by director of UK government relations Bob Keen.
Head of external comms Kate Watcham said: 'Subject to the company's internal processes and further discussions, BAE Systems intends to appoint Portland as an adviser to our UK government relations team. Bell Pottinger Public Affairs has performed that role for the past seven years and we would like to thank it for all its support during that period.'
Peter Bingle, BPPA chairman, said: 'We have done a superb job over the past seven years advising BAE Systems. We wish Bob Keen every success going forward.'
The six-figure account is a major coup for Portland, headed by Tim Allan, as the agency continues to build its client base in the UK and overseas. The account will be led by partner Oliver Pauley, who joined this year from Fleishman-Hillard.
The review follows the departure in 2010 of BAE director of parliamentary relations Simon Astley, now head of public affairs at Balfour Beatty. Astley was replaced in January this year by Scott Dodsworth from his role as senior account manager at Fleishman-Hillard.
It comes as BAE repitches its consumer account, currently held by Euro RSCG. The government affairs review also comes two years after BAE moved its financial and corporate PR account out of Bell Pottinger and into FD.
BAE's reputation in Whitehall and Westminster took a hit last year after it admitted to false accounting and making misleading statements in relation to investigations by the US authorities and the Serious Fraud Office.
The company agreed to pay a fine of $400m to the US Department of Justice and a further £30m under an agreement with the Serious Fraud Office.
There is no suggestion that the government affairs review is linked to the investigations or the subsequent payments.