SENATOR URGES ACTION TO STABILIZE STOCK MARKETS Sen. John Heinz, R-Pa, urged the Administration to take steps to reduce volatility in the financial markets, including suspending program trading and limiting daily trading on stock index futures. Heinz said margin requirements for index futures, now six pct, should be the same as for common stock and equities. He urged creation of a task force to be headed by former Federal Reserve chairman Paul Volcker to coordinate international credit and montary policies among major nations and stabilize interest rates at the lowest possible levels.