The account will include a business-to-business DM campaign aimed at educating employers about their role in running and maintaining work-based pension schemes.
The AAR is working with COI to draw up a shortlist of suitable agencies.
The campaign, which will be targeted at businesses of all sizes, will promote the role of the Pensions Regulator as the first point of call for information on pension schemes.
The DM campaign will also drive businesses to the regulator's website - www.thepensionsregulator.gov.uk - as well as encouraging employers to sign up to its newsletters.
The pitch comes ahead of the Government's latest proposed pensions reforms designed to ensure workers are saving enough for their retirement. If passed, the Pensions Bill will ensure that all workers are automatically enrolled into a national savings scheme and raise the pension age to 65 by 2020.