Lafarge, joined the list of companies taking advantage of historically low interest rates to lengthen the maturity on its debt on Tuesday, as the company offered to buy back up to Euro1bn of its debt in exchange for a new bond.  Lafarge offered to replace its 5.875 per cent 2008 issue with a new issue with a 10-year maturity.  The company said the purpose of the bond exchange was to "lengthen Lafarge’s average debt maturity without increasing the amount thereof and to create a more balanced repayment schedule, while taking advantage of current market conditions".  The new bond will be launched on July 8. BNP Paribas and HSBC are lead managers.