An internal Halliburton Co. investigation has uncovered handwritten notes suggesting that former employees considered offering bribes to Nigerian officials a decade ago to secure work in a $5 billion project to build a natural gas liquefaction plant.

The notes appear to record conversations among the former employees and their partners in a consortium called TSKJ, formed in the early 1990s to pursue work on Nigeria's Bonny Island project, an official of the Houston energy services company said yesterday. That consortium includes a company that became part of Halliburton subsidiary Kellogg Brown & Root Inc.

Wendy Hall, a Halliburton spokeswoman, said the notes show the consortium partners were discussing the possibility of bribes. But she said there's no evidence yet that any money exchanged hands.

Hall said almost all the documents date to before 1998, when Halliburton merged with Dresser Industries Inc. and acquired M.W. Kellogg Co. and the subsidiary involved in the Nigerian project. KBR was formed by the merger of that Dresser subsidiary with Halliburton's Brown and Root.

Vice President Cheney was Halliburton's chief executive at the time of the merger. Hall said there is no indication Cheney was aware of the apparent bribery scheme. Hall said the internal investigation, which began in February, has included interviews with about 50 employees.

"Our internal investigation uncovered some indications of a possible plan that would have routed money to certain Nigerian officials," Hall said in an e-mail.

"This was a long time ago," she said in an interview. "We are committed to getting to the bottom of this."

Company investigators found the notes in recent days, almost a month after Halliburton reported to investors that the Justice Department said it was expanding its probe of allegations that former employees accepted inappropriate payments relating to the same project. The Wall Street Journal reported the discovery of the notes yesterday.

The Securities and Exchange Commission earlier began its own investigation of whether those employees and their partners paid $180 million in bribes to secure the Nigerian work. In June, Halliburton fired two consultants, including the former chairman of KBR, saying they had accepted "improper personal benefits" in connection with the Nigeria project.

The Nigerian bribery probe is one of several investigations being conducted into Halliburton's global work, including allegations that it overcharged the U.S. government on large logistical contracts in Kuwait and Iraq.