, the owner of big British brands including Hovis, Mr Kipling, Sharwood's and Bisto, is still in talks with WCRS and McCann Erickson for the second place on the roster.
It is not yet clear how Premier Foods will split the brands between the agencies.
McCann Erickson is the only incumbent agency left in the running after CHI & Partners, Delaney Lund Knox Warren and Publicis all failed to make the final shortlist last month.
This was a particular blow for CHI, which handled the majority of the business including the Ambrosia, Loyd Grossman and Gale's Spread accounts, along with the £6m Branston range which it won last year without a pitch.
Premier Foods decided to slim down its advertising roster following the acquisition of its rival earlier this year. RHM owned the Bisto and Paxo brands among others.
It is understood that the company invited RHM incumbent agency DDB London, which handled the Hovis brand, to pitch but the agency declined to take part.
In July, Premier Foods consolidated its £26m media planning and buying account into MediaVest.