The company has a shortlist of agencies in contention for the accout and is thought to be close to making an appointment.
Westfield does not currently retain a CRM agency but is thought to be keen to boost its skills in this area in order to build a stronger relationship with its regular visitors.
The search begins ahead of the launch of Westfield's Stratford City development, which is due to open its doors in September. Westfield Stratford City will reportedly be the largest urban shopping centre in Europe, offering 1.9 million square feet of retail and leisure space.
Westfield is also currently reviewing its advertising business, having parted company with the incumbent, CHI & Partners, last month.
CHI, which had won the business in April last year, is responsible for Westfield's most recent ad campaign, introducing the brand's new "Fashion Lives" positioning.
Westfield previously used Adam & Eve to handle its advertising. However, the agency, which created work using the "Shopping in a new light" line, resigned the business after it won the John Lewis ad account in December 2009.
Other agencies on Westfield's marketing roster include The Viral Factory, which handles viral activity; Made by Many, which oversees digital advertising; and Yellow Door, which manages PR.