This excerpt taken from the NBR 10-Q filed Nov 2, 2006.
We have a substantial amount of debt outstanding
We had approximately $2.0 billion in debt outstanding as of December 31, 2005 resulting in a gross funded debt to capital ratio of 0.32:1 and a net funded debt to capital ratio of 0.08:1. Both of these ratios are a method for calculating the amount of leverage a company has in relation to its capital. As a result of the completion of the private placement of $2.75 billion 0.94% senior exchangeable notes due 2011 during the second quarter of 2006, and the redemption of 93% of our $1.2 billion zero coupon senior convertible debentures due 2021 during the first quarter of 2006, we have approximately $4.0 billion in debt outstanding, resulting in a gross funded debt to capital
ratio of 0.51:1 and a net funded debt to capital ratio of 0.37:1 at September 30, 2006. As a result of these transactions, we have increased our indebtedness by approximately $2.0 billion, which could adversely affect our senior unsecured debt rating, the ratings of our outstanding indebtedness and the value of our notes.