Environmental services are among those earmarked for merger by a new "super council" formed between Hammersmith & Fulham, Westminster and Kensington & Chelsea.
Working groups have been set up to assess how best to share environmental services, adult social care and corporate services, and their recommendations will be unveiled in February 2011.
Commenting on the plans, Hammersmith & Fulham council leader Stephen Greenhalgh said the aim was to "squeeze every penny and every pound" and warned that "nobody should be under any illusions about the difficulty of the challenge ahead".
In a joint statement, leaders from the three boroughs said: "Our plans may be the first of their kind, but sharing of services in this way can no longer be viewed as a radical concept. It will soon become the norm for local authorities looking for innovative ways to keep costs down while delivering high-quality front-line services."
Thinking outside the box was essential to maintain local services, they explained. "In this age of austerity we need to examine new ways of working, including sharing service provision with other authorities to deliver more for less."
Hammersmith & Fulham and Westminster had both already begun work on merging their education services.