The CIA believes Ansar al-Sharia was behind the September 11 attack on the US consulate in which four people died, including US Ambassador Christopher Stevens.
According to officials, the leaders of the AQIM movement have been travelling regularly to the desert town of Ghat in south-western Libya, close to the border with Niger, the Telegraph reports.
Their aim is to establish a foothold in Libya from which to launch attacks against Western targets, as well as gaining access to the large stockpiles of weapons, the officials said.
"Al Qaeda regards post-Gaddafi Libya as a wonderful opportunity to expand its terrorist franchise," the paper quoted a senior intelligence official, as saying.
"The organisation will become a lot more powerful if it can form an alliance with Libyan Islamist groups," the official added.