Complete coverage: Read all the stories and documents related to the SemGroup collapse.

SemGroup LP, once a shining light of privately held Tulsa energy companies, which actually was hiding a mountain of debt, finally will emerge as a publicly traded and leaner midstream oil and gas firm after 15 months of bankruptcy, officials said Monday.

A federal judge and majority of SemGroup creditors signed off on the company's reorganization plan Monday. The approval allows SemGroup to emerge from Chapter 11 bankruptcy as early as next month.

U.S. Bankruptcy Judge Brendan L. Shannon's confirmation echoed a strong yes vote from most of SemGroup's creditors. Those lenders in support held more than $4 billion of the company's secured and unsecured debt, the judge noted.

"The record reflects overwhelming creditor support for the plan," Shannon said at the conclusion of an 11-hour hearing in Wilmington, Del.

The new public SemGroup, however, will not be listed on a stock exchange until 2010. The reorganized SemGroup initially would offer about $1 billion in equity, according to reports.

So many SemGroup attorneys, creditors groups and other interested parties made their way to Wilmington that Shannon opened another courtroom for an audio and video feed. The hearing also was linked with SemGroup subsidiary SemCanada's bankruptcy proceedings north of the border.

A federal court affidavit filed by New York tabulator Financial Balloting Group LLC indicates that all of SemGroup's creditor classes favored the reorganization plan. The secured first purchasers, secured working capital, secured revolver, term lenders, senior notes claims and lender deficiency claims all approved the plan by large margins.

The first purchaser class, which includes oil and gas producers who were stiffed by SemGroup when they sold product on credit around the bankruptcy period, approved the plan by a 377-27 vote. The bankruptcy court's Official Producers Committee signed off on the deal when a settlement promised more than $300 million last month.

The secured revolver/term lender category, representing more than $708 million in debts, tallied 90 creditors in favor and only two against. One of those opposing the plan disclosure was Bank of Oklahoma, which is owed $10.4 million under that creditor class.

Bank of Oklahoma also rejected the plan under its lender deficiency claimant status. The Tulsa-based financial institution is owed $43 million by SemGroup within that creditor class, according to court records.

The bank's parent company, Tulsa-based BOK Financial Corp., was forced to turn a second-quarter 2008 profit into a loss due to its $147 million credit exposure to SemGroup, according to reports. About $97 million of that BOK credit was tied in SemGroup's energy derivative contracts.