LONDON (Dow Jones)--BP PLC (BP) won't release next week preliminary findings from its internal investigation into the explosion aboard the Deepwater Horizon drilling rig that triggered the three-month-long oil spill into the Gulf of Mexico, a spokesman for the company said Tuesday. BP will publish its second-quarter results next Tuesday and analysts expect the company to address many of their concerns about how much the spill will cost BP and how it will pay for it. Press reports also suggested that BP would release preliminary results from its investigation into the causes of the accident, but BP hasn't publicly confirmed this. BP expects its investigation to conclude in September or October, the spokesman said. Federal authorities investigating the spill are focusing on bad decisions, missed warnings and worker disagreements in the hours before the blast. In particular, the panel is examining why rig workers missed telltale signs that the well was close to an uncontrolled blowout, according to an internal document assembled by the investigators. -By James Herron, Dow Jones Newswires; +44 (0)20 7842 9317; [email protected] (END) Dow Jones Newswires July 20, 2010 05:12 ET (09:12 GMT)