Corporate issuers from Blackstone Group LP to Royal Dutch Shell Plc are leading offerings of at least $4.6 billion by selling their first bonds in two years with yields at about record lows.

Shell, Europe's largest oil producer, is planning a three-part offering that includes 30-year debt through its international finance unit, and New York-based Blackstone is borrowing for the first time since September 2010 and issuing its first 30-year obligations. Dollar-denominated offerings have averaged $6.7 billion a day this month through last week, 8 percent higher than in July, according to data compiled by Bloomberg.

Companies including Philip Morris International Inc. and American Express Co. are exploiting investment-grade borrowing costs that dropped to an unprecedented 3.03 percent this month, according to Bank of America Merrill Lynch index data. Investors are giving companies the opportunity to issue low-cost debt by plowing money into the securities that yield more than U.S. government bonds, according to James Lee of Calvert Investments.