Kanye West, a key player in Jay Z's Tidal stable, has left the company over a money dispute and Tidal has threatened to sue him ... TMZ has learned. Sources connected to Tidal tell TMZ, Kanye has been unhappy with the company for a long time. We're told Kanye has complained the company owes him money -- more than $3 million. Our sources say a month ago Kanye's lawyer sent a letter to Tidal, saying the company was in breach and the contract was terminated. Over the next 2 weeks lawyers for both sides tried to resolve the conflict but failed. We're told 2 weeks ago Kanye's lawyer fired off a second letter declaring again the contract was over. Kanye's decision to split from Tidal predates the release of Jay Z's album in which he trashes Kanye, and we're told Kanye had no advance knowledge of Jay's lyrics. We're told Kanye's beef with Tidal is twofold -- his Saint Pablo album resulted in 1 1/2 million new subscribers to Tidal, for which he was supposed to get a bonus but the company hasn't paid. Kanye also says Tidal reneged on reimbursing him for music videos. Our sources say Tidal's position is that Kanye didn't deliver the videos required by the contract. Kanye's response ... I'll deliver the videos when you pay me what I'm owed. We're told Tidal fired off a letter to Kanye, saying as far as the company was concerned it still had an exclusive contract with the rapper and if he tried to go to another streaming service they'd sue him. We're told Kanye's willing to walk away, but if Tidal sues him, he'll sue them right back.