Companies tapped the credit markets for more than$48 billion in new bond issues last week in one of the busiest weeks for corporate debt on record.

Phillips 66 led the charge with $5.8 billion in four issues, ranging from three- to 30-year maturity. The money will be used for a cash payment to parent ConocoPhillips (NYSE: COP) as part of its upcoming spinoff.

A DirecTV (Nasdaq: DTV) subsidiary, meanwhile, floated $4 billion worth in three tranches with maturities of five, 10, and 30 years. The Use of Proceeds statement states that the funds "will be used for general corporate purposes, which may include a distribution to our Parent for its share repurchase plan." Four billion would make a serious dent in the float if all of it went to a share buyback.

Newmont Mining (NYSE: NEM) dug up some new funding, too, with $2.5 billion of new 10- and 30-year paper. The company plans on paying off its revolving credit, settling some swap contracts, and paying off a sale-leaseback agreement on an ore treatment plant. That'll leave well over a billion for "exploration, the development of our project pipeline or dividends, or other forms of capital return to our shareholders."

And CenturyLink (NYSE: CTL) dialed up buyers for a little over $2 billion in 10- and 30-year paper. The money will be used to refinance existing debt and end up with a lower average interest rate and longer average maturity.

Finally, Hewlett-Packard (NYSE: HPQ) rounded out the top five U.S. borrowers, with $2 billion in new bonds. The money will be used for "general corporate purposes, which may include the repayment of our currently outstanding commercial paper."

In addition to those U.S. companies, financial firms based outside the States kicked in nearly a quarter of the borrowing binge. The big borrowers beyond our borders were Commonwealth Bank of Australia, Toronto-Dominion, Royal Bank of Canada, Singapore's OCBC, and Japanese companies Mitsui Sumitomo and ORIX.

Corporate borrowers continue to bring plenty of bonds to market, and foreign borrowers have been taking up sizeable chunks of the low-rate dollars on the table. I think bond buyers are taking on quite a bit of interest-rate risk at current levels, and investors should think carefully before lending money at near record-low rates.