According to the Sun, the offer could be too good to turn down.
"This is something Conor's always wanted to do. The WWE guys have asked him to do shows before with them but the timing was never really right.
"But this time it looks like a deal is going to be locked into place. He has some things to tie up in the UFC before he can do anything else but this is a big money deal so I can't see him turning it down."
McGregor revealed in February that he was approached by WWE management but turned them down to prepare for the Mayweather fight - his boxing debut.
"Never say never. I'd love to go into that WWE and have a real knock," he said at the time.
"Let one of them have a real knock and see what's what. But we'll see. There's conversations ongoing. I've turned down some things, the conversation's still ongoing."
The move could prove to be a heated affair after McGregor upset a number of WWE stars when he referred to them as "messed up pussies" during a promotional event for his UFC 202 fight against Nate Diaz in August last year.
Following the comments, former WWE champion Ric Flair called out McGregor on social media.
McGregor would not be the first man to jump between the UFC and WWE. In 2008 WWE superstar Brock Lesnar signed with the UFC having headlined at Wrestlemania just four years prior.
Also, in 2008 Floyd Mayweather made his WWE debut when he fought The Big Show at Wrestlemania 24.
