The fuel giant awarded the assignment last week after a pitch involving a mixture of direct marketing and sales promotion specialists.
Iris will work alongside Proximity on a series of ad hoc projects.
Overseen by Raoul Pinnell, Shell's vice-president of global brands and communications, the pitch was designed to assist the company's integration of its below-the-line strategy more effectively with advertising developed by Shell's global agency J Walter Thompson.
Work will concentrate on point-of-sale material at thousands of Shell petrol forecourts around the world, as well some direct and promotional marketing.
The unsuccessful agencies involved in the pitch were J Walter Thompson, Triangle Communications, Tullo Marshall Warren, KLP Group and Toast.
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