Sharon Stone has lashed out at business moguls who pledged thousands of dollars towards helping fight malaria but refuse to pay up. The BASIC INSTINCT star urged the corporate tycoons to delve into their pockets in an impassioned address at the World Economic Forum 18 months ago. Stone hoped the funds would provide mosquito nets in malaria hotspots, and donated $10,000 (GBP5,555) to the cause herself. But despite reaching her $1 million (GBP555,555) target on the day, just $250,000 (GBP138,888) has been paid so far. Now she's furious on hearing the United Nations Children's Fund (Unicef) have been forced to make up the shortfall with their own funds. Her spokeswoman CINDI BERGER says, "I am sure that they (businessmen) thought with their hearts when they raised their hands. "Now they should be honourable and open up their wallets as they pledged to do so."