The organisation is planning to appoint an agency or agencies for a term lasting up to five years, with annual renewal options. It has issued separate tenders for each country, with a deadline of 9 April for responses.
InterTradeIreland is funded by both countries and was set up in the years after the Good Friday agreement between the British and Irish governments in 1998 that cemented the peace process.
Its aim is to improve business results and competitiveness, stimulate economic performance and help create jobs across Ireland.
The projected spend on PR services as part of the account was not disclosed, but it is understood that during the past five years the organisation has allocated €200,000 (£172,000) in Northern Ireland and €370,000 (£318,200) in the Republic.
The incumbent agencies are Davidson Cockcroft Partnership in Northern Ireland and Drury Communications in the Republic.
Both tenders cover a range of services, from ongoing comms advice and support to media relations, public affairs advice, media training, crisis management, PR campaigns and comms training.
The organisation is aiming to build on the level of awareness that businesses across Ireland have of it, which has increased from 38 per cent in 2007 to just over 55 per cent currently.
Its public affairs needs revolve around engaging trade ministers in both countries, amid continuing financial uncertainty. Other stakeholders include special advisers and officials in all relevant departments, the North South Ministerial Council and relevant spokespeople in the two legislatures.