To many, it seemed that possibly illegal collusion to reduce competition had occurred.

An agreement among the airlines themselves to cut service would be illegal collusion, officials said.

Any kind of dealing or contact, or a "meeting of the minds" between parties could potentially be counted as illegal collusion.

Any illegal collusion could involve tens, if not hundreds, of millions of dollars.

A British investigation into the CD market four years ago similarly found no proof of illegal collusion among the music majors there.

The Justice Department is investigating whether those spreads reflect illegal collusion among market makers.

Judge Patel wrote that if Napster shows the record labels were involved in illegal collusion, it could invalidate their lawsuit.

If any staked player fails to compete against a stablemate as hard as he does against other opponents, illegal collusion occurs.

As to the charge of an illegal collusion to divide software markets, Mr. Gates said only, "I think somebody said that was in there."

Whether that coaching and guidance crosses the line and becomes illegal collusion is for the players association to determine.