Grosvenor has appointed PR company Weber Shandwick to handle public relations for its Liverpool One scheme as part of a £1.5m deal.
The company, which has an office in Manchester, is replacing previous account holders Mason Williams.
As part of the deal, McCann Manchester will oversee the advertising accounts for the retail destination.
The agencies won the business following a four stage pitch process this summer.
Donna Howitt, marketing director for Liverpool One, said: "The pitch process has been extremely insightful. Both agencies understood our brief from the outset, they weren't afraid to challenge us and they clearly demonstrated quality and depth of knowledge in every element of the pitch from insights and planning, right through to the creative ideas and execution."
The PR account will be led by Weber Shandwick's consumer account director Hayley Corbett, who will work alongside Weber's managing director, Jo Leah, on strategy and planning.
Leah, said: "We are very pleased to be back in Liverpool working for such a prestigious destination and can't wait to start our campaign, which has exciting new ideas that will take Liverpool One to new audiences in new markets."
Dave Donaghue, managing partner at Prestbury-based McCann Manchester, will lead an account team of 11 people at McCann Manchester who will deliver an integrated creative campaign.
The agencies are also working on four year marketing campaign with in-house firm Media Vest.