PROVO — Professor Steven Jones and Brigham Young University finalized a retirement package Friday, six weeks after the school placed the physicist on paid leave to review his statements and research about the Sept. 11, 2001, attacks on the World Trade Center.

"I am electing to retire so that I can spend more time speaking and conducting research of my own choosing," Jones said in a statement released by the university. "I appreciate the wonderful opportunity I have had to teach and serve and do research at BYU for more than 21 years."

Jones and BYU worked on the package for weeks, Jones said in an interview with the Deseret Morning News. The university abandoned its review of his 9/11-related work Friday after the agreement was reached, university spokeswoman Carri Jenkins said.

Jones' retirement is effective Jan. 1. He hasn't decided what he'll do next, though he has received a feeler from another school and intends to keep talking about the 9/11 terrorist attacks.

Both sides declined to release details about the retirement package, but Jones said he was told it was pretty standard.

"The university's been great," he said. "I feel like they've been fair with me in this settlement we've reached in this retirement. I feel pretty chipper."

Jenkins said BYU's aborted review, which was expected to last the rest of the semester, was still in the early stages.

"It was at the department level, and we were still in the process of putting together a review panel," she said.

Jones submitted a letter to the editor of the Deseret Morning News via e-mail Friday afternoon. Written two weeks ago, the letter did not mention his decision to retire and avoided any reference to BYU. In it, Jones renounced the Iraqi War, questioned the official explanations of the collapses of the World Trade Center towers and expressed concern that a future terrorist attack might be blamed on Iran or Syria to justify American aggression against those nations.

"I stand firmly against the war in Iraq and any war of aggression," Jones wrote. "I support scientific scrutiny of the events of 9/11/2001, a day which will live in infamy."

BYU stripped Jones of two classes he was teaching when the university placed him on paid leave on Sept. 7 to review a paper he wrote about the physics behind the collapse of three towers on Sept. 11. He published a paper saying experiments he conducted at BYU on material from ground zero and other evidence led him to believe the towers fell because pre-set explosives were detonated throughout the buildings after the hijacked jets struck the Twin Towers.