providing a revolving credit facility of $ 7.0 billion and expiring on october 17 , 2008 . interest on any amounts we borrow under these facilities would be charged at 90-day libor plus 15 basis points . at december 31 , 2007 , there were no outstanding borrowings under these facilities . our existing debt instruments and credit facilities do not have cross-default or ratings triggers , however these debt instruments and credit facilities do subject us to certain financial covenants