McCann, a Scots-born Canadian who has turned the club's finances around since taking control in 1994, said in a statement released on the London Stock Exchange that he would retire in mid-1999.
"Suggested take-overs are complete nonsense as I hold just over 50 per cent of the ordinary shares. That makes a takeover impossible without my consent," McCann said.
"Ideally I would like to find a way to make some of my shares available to existing shareholders. However, I think the most likely scenario will be a mixture of existing shareholders and institutions. What I will guarantee is that ownership of the club will not fall into the wrong hands."
When McCann bought 146,000 shares, a 51 per cent stake in Celtic, for pounds 9m in 1994, he said the club faced bankruptcy, had a very poor stadium and only 7,100 season ticket-holders.
They are now close to completion of a pounds 30m stadium with seating for more than 60,000, making it the largest in Britain.
The club was now financially secure, more than pounds 20m had been invested in new players and there were 40,000 season ticket-holders, he said. Celtic shares are currently quoted at pounds 250 pounds each.
The Celtic coach Wim Jansen hopes the imminent arrival of Harald Brattbakk will help to put his team back into title contention at Pittodrie tonight.
With the Norwegian due in Glasgow on Thursday to complete his pounds 2m move from Rosenborg, the likes of strikers Simon Donnelly and Darren Jackson will be under extra scrutiny against Aberdeen.
After Saturday's 0-0 draw at Kilmarnock, another blank would put a serious dent in Celtic's hopes of maintaining a championship challenge.
Already six points behind Rangers and seven behind leaders Hearts, Jansen knows his men cannot afford any more slip-ups against Alex Miller's strugglers.
Winger Regi Blinker returns after serving a one-match suspension and looks likely to be asked to provide the ammunition for a lacklustre front line.
Jansen said: "I hope the strikers give me a problem when Harald arrives. If we want to get up the league we know we have to win these type of games and if we lose points here then we make problems for ourselves.
"The whole team didn't really look as sharp on Saturday as they did in our two games against Dundee United.
"The way we play they need to be sharp to get back to winning games but it is the individuals in any system that make the difference."
Sweden's Henrik Larsson looks the most likely partner for Brattbakk when he is ready for action, but Jansen may decide the time has come to give Jackson a place from the start after three substitute appearances on his return from brain surgery.Reuse content