Powergen UK comms head Isobel Hoseason refused to rule out PR job losses as the two companies merge and it is understood the TXU side - headed by TXU Europe vice-president of comms Rachael Reid - will be hardest hit.
TXU has around 15 comms staff to Powergen's seven.
Powergen PR, sponsorship and CSR manager (retail) Zoe Coombs conceded that 'rationalisation' of agency relationships was on the cards given future integration of TXU's three consumer-facing brands - TXU energi, Staywarm and Amerada - and their agency requirements.
Powergen's retail business has retained Lexis PR for around three years and TXU has retained Manning Selvage & Lee for PR on energi.
Coombs insisted that Lexis's contract was not under immediate review and that she was content with that agency's work.
However, MS&L's work is likely to be reviewed, as is that of MCG PR, which TXU has used on a month-by-month project basis for its Staywarm brand. It has not used a PR agency for its third brand, Amerada.
It is understood that Staywarm is the only brand likely to remain after integration with Powergen is completed.
Powergen uses Weber Shandwick for internal comms work and Fishburn Hedges for public affairs support. Hoseason stressed these contracts were not under review.
TXU used Westminster Strategy for public affairs support until last autumn when its contract was not renewed.
Powergen, owned by German utility giant E.on, bought TXU's UK retail arm and three coal-fired power stations for £1.37bn. The deal was announced in October and went through last month.