The advisory body aims to revitalise regional museums, link libraries to the internet and implement the Government's ten-year library plan, Framework for the Future.
Citigate Public Affairs has scooped the body's political monitoring contract, while Kinross + Render has bagged a media relations brief.
The accounts, which are for an initial one-year period, are led by Citigate Public Affairs director Rex Osborn and K+R executive chairman Sara Render, both reporting to the council's external relations director Louise de Winter.
The council's incumbents, GCI London on the political side and Brunswick Arts for media relations, both lost out in the repitch.
De Winter said: 'The political monitoring brief offers us a more analytical account of political developments. We wanted parliamentary monitoring more tailored to us and our issues - such as education, learning, skills and sustainability.'
Citigate will monitor policy announcements and provide analysis of their potential impact.
Explaining the hire of K+R, de Winter said: 'We have a very small team doing media relations, with only one full-time person. We want to build our profile in national newspapers and trade press in related areas such as digitisation.'