In the US, the lawsuit could cost Apple billions of dollars.
IBM is expected to file a $1bn suit against Apple in the US on Monday.
The court case has been quietly brewing for weeks, and a report last week suggested the two companies might even be negotiating a deal.
Apple and IBM have already made it clear that they do not want to work together, with IBM reportedly pushing to break up Apple’s Macintosh division.
Apple’s lawsuit would be one of the first major lawsuits against IBM to come out of the US in a long time, and could also force IBM to change its ways in the chipmaker’s market.
The company has been working on a legal strategy that would see it bring a lawsuit in the courts in the United States.
Apple could also sue for breach of contract if IBM did not make a commitment to sell the Mac, according to sources close to the situation.