(The Wall Street Journal) -- If credit-market troubles make it harder for companies to borrow, the raft of share buybacks that has been helping to buoy the stock market could become a thing of the past.

Companies have been buying back shares at a breakneck pace, repurchasing a record $122bn (€88bn) of stock in the second quarter alone, according to Standard & Poor's estimates. Those buybacks have helped propel the stock market higher because they have reduced the supply of shares available to invest in and, in doing so, have also raised per-share earnings.