FED MAY ADD RESERVES TO BANKING SYSTEM The Federal Reserve may intervene in the government securities market to supply temporary reserves indirectly via customer repurchase agreements, economists said. They said that while the Fed faces no great urgency to add reserves at the start of the two-week maintenance period today it would probably do so in order to offset a relatively high federal funds rate. Fed funds opened at 6-3/16 pct and remained there in early trading. Yesterday, they averaged 6.45 pct, after rising as high as seven pct at the close.