The company currently retains Countrywide Porter Novelli and Lexis PR but is planning to hire 'two or three' additional agencies by early 2003.
The augmented roster will share an annual PR spend that could surpass £4m, according to Diageo GB media relations director Lindsey Sexton-Chadwick.
She stressed that Diageo was satisfied with CPN and Lexis and that their retained contracts were not under threat.
Sexton-Chadwick confirmed the additional agencies would be hired on retained contracts, saying: 'We need agencies that we can build a relationship with.'
Lexis has worked on the Guinness and Archers brands for around two-and-a-half years. CPN has also worked on a selection of brands now under the Diageo banner for at least two years. Among other campaigns, it has recently handled PR work for Smirnoff and, this summer, a campaign for Pimms.
Other brands in the Diageo stable include Baileys, Bell's whisky, Gordon's gin, and a range of fine whiskies branded as the Six Classic Malts.
In addition, Jose Cuervo tequila, J&B, Captain Morgan rums and non-alcoholic lager Caliber are among the brands up for grabs.
Sexton-Chadwick said Lexis's work for Guinness and Archers would not be affected. She said it was possible CPN could lose work, 'though that is not the intention'.
'This is more about incremental growth of our PR work, rather than cannibalisation (of existing contracts),' she added.
A shortlist of around ten agencies, 'with very different skill-sets,' will be drawn up before the end of the year.
'We are coming up to the Christmas period, the busiest trading time of the year, and are planning to see the agencies in January,' said Sexton-Chadwick.