Trade and oil considerations played a major role in the decision to include the Lockerbie bomber in a prisoner transfer agreement between Britain and Libya, a senior British official said in an interview published Saturday. Justice Secretary Jack Straw said trade, particularly a deal for oil company BP PLC, was “a very big part” of the 2007 negotiations that led to the prisoner deal. The agreement was part of a wider warming of relations between London and Tripoli. The British government has faced intense criticism over the release of Abdel Baset Al-Megrahi, a Libyan convicted in the 1988 bombing of a Pan Am airliner over Lockerbie, Scotland. The attack killed 259 people aboard the plane, most of them American, and 11 on the ground. Last month Scottish officials freed Al-Megrahi, 57, on compassionate grounds because he is dying of prostate cancer. Asked whether trade was a factor in his decision to include Megrahi in a prisoner swap deal with Libya, Straw told the newspaper: “Yes ... a very big part of that. I am unapologetic about that. Libya was a rogue state. We wanted to bring it back into the fold. And yes, that included trade because trade is an essential part of it and subsequently there was the BP deal.” Documents released this week show Straw initially opposed including Megrahi in the prison transfer agreement due to opposition from Scotland – but changed his mind, citing “wider negotiations” with Tripoli. At the time, talks on the ratification of a huge oil deal between BP and Libya had become bogged down. The $900 milliondeal was ratified in Jan. 2008 shortly after Straw's change of mind. BP said Friday it had lobbied Britain to speed up the agreement with Libya to improve business relations, but denied pressing for Megrahi to be released. The Scottish government, which has devolved powers for justice and other areas, freed Megrahi for compassionate reasons rather than using the prisoner transfer agreement. The British government has sought to distance itself from the decision, saying it was solely a matter for Scotland. On Wednesday, Brown said there was “no cover-up, no double-dealing, no deal on oil”, while his effective deputy, Peter Mandelson, described suggestions that the release was linked to a trade deal as “offensive”. Documents released last week by the Scottish government showed Libyan officials had warned London the death of Megrahi in jail would have “catastrophic effects for the relationship between Libya and Britain”. British firms have become heavily involved in exploring for hydrocarbons in Libya after UN sanctions were lifted in 2003. Al-Megrahi was the only person convicted of the bombing of a Pan Am passenger jet over the Scottish town of Lockerbie that killed 270 people in 1988. His early release and warm welcome home in Tripoli triggered an international row that Brown's political rivals said damaged relations between London and Washington. Straw said Brown had not been involved in negotiations over the prisoner agreement. “I certainly didn't talk to the PM,” he was quoted as saying. “There is no paper trail to suggest he was involved at all.”