FED EXPECTED TO ARRANGE SYSTEM REPURCHASES The Federal Reserve is likely to add temporary reserves to the banking system this morning by executing system repurchase agreements, economists said. The Fed faces a need to add a large volume of reserves this statement period to offset a drain caused by rising Treasury balances at the Fed after the June 15 tax date. Most economists are predicting over-the-weekend system repurchases. But some, who see a smaller adding requirement, are forecasting a less aggressive combination of three- and six-day repos. Fed funds were trading at 6-3/4 pct, close to yesterday's 6.81 pct average.