Three months ended December 31, September 30, Sequential 2023 2023 change (In millions, except per share amounts and backlog) Contract drilling revenues $741$ 713 $28 Adjusted contract drilling revenues$ 748 $721$27 Revenue efficiency 97.0 % 95.4 % 1.6 % Operating and maintenance expense $569$ 524 $45 Net loss attributable to controlling interest$ (104 ) $(220 )$116 Diluted loss per share $(0.13 )$ (0.28 ) $0.15 Adjusted EBITDA$ 122 $162$(40 ) Adjusted EBITDA margin 16.3 % 22.5 % (6.2 ) % Adj ...