Sept. 27 (Bloomberg) -- BHP Billiton Ltd. was able to extend the maturity of its debt in a $5 billion sale, showing investor demand for mining bonds even as...

Sept. 27 (Bloomberg) -- BHP Billiton Ltd. was able to extend the maturity of its debt in a $5 billion sale, showing investor demand for mining bonds even as much of Australia frets that the best of a record resources boom is over. Half of the securities sold this week by Melbourne-based BHP had a tenor of 30 years, compared with just 19 percent at its previous U.S. sale in February 2012. The 2043 notes were sold to yield 5.001 percent, compared with an average of 6.353 percent on bonds maturing in 20 to 30 years among debt in Bank of America Merrill Lynch's U.S. Metals, Mining & Steel Index. BHP 5 year CDS is opening 73/77 at the open in London. Rio 5 year opens 108/114