Mckay could sign for the Sky Bet Championship side before the weekend if the Northern Ireland international agrees terms following a reported £150,000 bid.
The striker had made it clear to Inverness that he would not extend his contract beyond the summer and Caley Thistle are looking to cash in now.
Chairman Kenny Cameron told ictfc.com on Wednesday morning: “Following an approach from Wigan Athletic FC late yesterday afternoon and following discussions with the management team, the board of Inverness Caledonian Thistle FC agreed to allow Billy Mckay leave to travel to DW Stadium for discussion of personal terms with a view to an immediate transfer.
“Billy has never hidden his ambition to compete at the highest possible level and has always conducted himself in a professional manner in this regard.
“We are grateful to Wigan Athletic FC for the courtesy shown in speaking to us before opening their discussions with the player.”
The 26-year-old has scored 59 goals in his last two-and-a-half seasons in Scotland and has started all but one of his club’s games this term.
The former Northampton player enters talks with Wigan on the back of a run of scoring nine goals in 13 games and ahead of a weekend which could see Caley Thistle move one point behind Scottish Premiership leaders Celtic.
But Cameron insists that the club can cope with his loss.
“We are forever mindful of the risk of losing players during any transfer window and, as always, have contingency plans in place should agreement on personal terms be reached with Billy,” he said.
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