United Airlines will delay filing its annual financial report — initialy due today — for up to two weeks, saying it is still working through tax accounting related to its bankruptcy.

The carrier, which emerged from bankruptcy in February of last year, said in a regulatory document that it intends to file the report by March 16.

"As a result of complications from its bankruptcy reorganization, the company is not able without unreasonable effort or expense to conclude all of the processes and procedures necessary for it to complete the preparation of its tax accounting," United said in the statement.

All publicly traded companies are required to file an annual report with the U.S. Securities and Exchange Commission. The documents included detailed information about a company and its finances.

United, which is a unit of Chicago-based UAL Corp., also said today that it is joining the Nasdaq 100 Index on March 8, replacing American Eagle Outfitters Inc.