It is understood that the retail giant has sent out an RFP requesting agencies respond to questions covering food, general merchandise and the supermarket’s value offer.
Tesco blamed a "weaker grocery market" on its 2.4 per cent fall in like-for-like UK sales in the six weeks to 4 January, the crucial Christmas sales period.
Group sales at the UK's largest supermarket were down 1.1 per cent excluding fuel.
Tesco also cited the opening of fewer new stores and the revamp of non-food ranges as contributing factors in the decline in performance.
Agency sources have speculated that the RFP may be the first stages of the company building a UK consumer roster.
Tesco was yet to issue a comment at the time of publishing.