The driller filed a Chapter 11 petition in U.S. Bankruptcy Court in Delaware, indicating its estimated liabilities to be up to $1 billion.
Sunday’s filing comes two days after shareholders of HighPoint and Bonanza approved plans for the companies to merge as part of a prepackaged debt restructuring agreement. Bonanza’s stock tumbled 12% last week, paring its gains this year to 81%. A phone call requesting comment on Sunday was unanswered.