Tony Blair was one of the leaders present at the forum
Speaking ahead of the G8 summit of industrialised nations, they said they wanted a market in which carbon prices were transparent and consistent.
The idea of carbon trading is that firms can either cut emissions or buy the right to keep polluting.
It is hoped that such a global market would encourage the development of cleaner technologies.
"I believe that unlocking the ability of a competitive market to innovate and change behaviours will achieve the lost cost solution to climate change," said Tony Hayward, the newly appointed chief executive of BP.
Energy sector leaders are keen that there should be a single price for carbon emissions throughout the world.
They were taking part in a two-day event in Berlin organised by the environmental network Globe International ahead of this week's G8 summit.
It was attended by legislators and business leaders from the G8 countries as well as emerging economies such as Mexico, Brazil, China and India.