France is to step up efforts to instil moral values in the global market economy by urging policymakers to consider fresh ways of combating financial short-termism.

Nicolas Sarkozy, France's president, and Tony Blair, the former UK prime minister, will jointly host a conference in Paris next week of political leaders and Nobel prize-winning economists to discuss ways of strengthening the ethical foundations of the capitalist system after the financial crisis.

"There is no system of wealth creation without a system of values and this value system has been badly shaken," said Eric Besson, the French minister for policy planning, who is organising the conference.

"People are prepared to accept others getting high pay and enjoying different lifestyles, but only if they have the feeling that the system is fair and that the law is the same for everybody."

Mr Besson criticised complex securitisation of debt, excessive financial leverage, short-selling and demands for unrealistic returns on investment, saying they pointed to a pervasive "failure to value the long term" across all sectors of the economy for the past 20 years. "Nobody wants to ban the stock market," he said, even though it had become a "casino".

"But how can we return to certain fundamental values where the stock exchange is the place businesses come to for the long-term capital they need?"