Celtic have regularly conducted business with City by signing the likes of Jason Denayer, John Guidetti and Dedryck Boyata from the Etihad Stadium side in recent seasons.
Deila has now gone on to reveal that he has a very strong relationship with City, stemming from his days in Norway, and is hopeful that he can use the link to bring in a couple of more players to Parkhead in the future.
Deila said: "It's a relationship. A relationship that I have had for many years, since Stromsgodset.
"We trust each other in the way we have developed players for them. And if they can bring quality into our squad like Jason did and Guidetti as well then it's positive for both of us.
"Now we know that, if we're going to do things like that, we have to have an arrangement that is over the summer and for a longer period. If it happens, then there has to be something special we need at that time, to the summer, or else it's going to be a longer loan."