FORTUNE – Google and Apple have called a truce in a long-running patent dispute, ending a high-profile legal battle between two Silicon Valley titans over smartphone technology.

“Apple and Google have agreed to dismiss all the current lawsuits that exist directly between the two companies,” the two companies said in a joint statement late Friday.

Google’s Motorola Mobility unit started the fight in 2010 by suing Apple for patent infringement. Apple AAPL responded by counter suing, ushering in an era in which major technology companies spent huge resources fighting each other in court. Google GOOG inherited the lawsuit when it acquired Motorola in 2012 for $12.5 billion. It has since agreed to sell off the unit to Lenovo, the Chinese computer maker, for $2.9 billion while keeping Motorola’s patents.

The lawsuits and counter suits – nearly two dozen in all globally – highlighted the increasing tensions between Google and Apple, which had been allies at one time. But their growing rivalry in everything from mobile devices to online maps to laptop computers left the relationship in tatters and an army of attorneys busy in court.

Google, arguing that Apple had infringed on its patents, had tried to get injunctions to force Apple to stop selling the iPhone. Apple argued that parts of Google’s Android software took their cue from the iPhone’s operating system.

In dropping the suits, the companies may have simply come to the conclusion that it was no longer worth the bother. With Google selling Motorola, neither side had much of an incentive for years of further litigation.

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In the statement, the two companies said they would work together in some areas of patent reform. Big Silicon Valley companies, despite their rivalries, are largely united in their critique of the patent system and the desire to change it to reduce lawsuits by so-called patent trolls – small companies whose livelihood is largely from pursuing patent infringement claims.

Apple and Google said they had not agreed to cross-license their patents to each other. If they had, it would have been a sign of unusual cooperation between two rivals. Apple and Google, together, dominate the smartphone market. Apple does so with its iPhone while Google’s power lies mostly in its operating system, which it licenses to a number of mobile phone manufacturers.

Apple’s agreement to make nice with Google does not extend to Samsung, a Google Android partner. Earlier this month, Apple received a $120 million judgment against Samsung for patent infringement.