The insurance brand, which handed its creative work to McCann Erickson Bristol in June, is understood to be planning activity including an outdoor and press ad campaign.
AIG's low UK profile was boosted this year when it signed a four-year shirt sponsorship deal with Manchester United worth £56.5 million - the biggest of its kind in UK football history.
The insurance giant lacks presence in the UK consumer market, having focused on the business-to-business market. However, PHD North will now work on leveraging the value of the Manchester United deal for AIG.
Earlier this year, AIG said it planned to build a marketing strategy around the tie-up. Manchester United will feature in the company's marketing across global markets.
AIG has a strong presence outside the UK, particularly in China and Japan, and is also hoping to benefit from the deal in those territories. Manchester United estimates that 40 million of its 74 million fans worldwide live in Asia.