According to court documents filed late on Monday, Lehman's initial 120-day exclusivity period will run out on January 13, and if the court does not grant the request, creditors or other parties could propose competing plans. Bankruptcy courts often grant such extensions for large, complex cases.

Lehman filed for bankruptcy protection on September 15, in the largest U.S. bankruptcy filing in history, listing more than $600 billion in assets. It has since sold many of its core assets but is still working to unwind thousands of derivatives, open trades and intercompany transactions.

The company said its limited employees must recover and review 2,000 terabytes of data that would completely fill 20,000 computers to the maximum and that it has also faced challenges relating to at least 76 foreign insolvency proceedings that have been initiated in over 15 countries since it filed for bankruptcy protection.

An extension is "absolutely necessary," Lehman said in the court papers, as it believes neither the company or any other party of interest in the case could come up with a plan and build consensus among the company's vast creditors for that plan in just 120 days.

A court hearing on the request is set for January 14, according to the documents.

(Reporting by Santosh Nadgir in Bangalore; Editing by Deepak Kannan)