The move has come as a shock to Lend Lease who were unveiled as the original development partner for the Friary Shopping Centre in March.
The U-turn is expected to be confirmed at a council meeting next month.
Land Securities and Lend Lease originally submitted plans alongside rival developer Queensberry Real Estate.
Land Securities will now work with the council and the centre’s owners M&G Real Estate.
Cllr James Palmer, Deputy Leader of the Council and Lead Councillor for Town Centre Planning and Infrastructure said: “Following the Evaluation Panel’s initial selection of a potential development partner, we carefully re-examined our original recommendation in light of the recent site acquisitions by the Prudential through its property fund M&G.
“The Panel assessed the developers’ compatibility with the primary landowners together with evidence of relevant and recent experience, capability and an appreciation of our development objectives.
“In reconsidering our decision, the Panel has reached a different conclusion, which we believe brings forward the most timely and effective development programme with the primary landowners and the right development partner.
“Presentations by the shortlisted developers and engagement with local interested parties helped to inform the Panel in reaching their decision.
“This recommendation aims to move the North Street project forward at pace with Land Securities working closely with the Council and its landowner partners.”