The estimate was revealed in a court filing early Tuesday, six days before the world's largest consumer electronics companies are scheduled on July 30 to begin a jury trial before U.S. District Judge Lucy Koh in San Jose, California.

Apple accused Samsung of infringing its patents by making its popular Galaxy phone and computer tablets "work and look" like Apple products, enabling the South Korean company to overtake it as the world's largest maker of smartphones.

Samsung has countered that it simply developed its own "unique" products in a bid to "best the competition," and that Apple actually owes money for using its patented technology.

In its court filing, Apple said Samsung owes "substantial monetary damages" because it illegally "chose to compete by copying Apple."

It said Samsung has been "unjustly enriched" by an undisclosed amount -- presumably $2 billion -- and deprived Apple of $500 million of profit and $25 million of reasonable royalty damages. This results in "a combined total of $2.525 billion" of damages, Apple said.

Apple called its estimates conservative, and still plans to pursue a permanent injunction to stop future violations.

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Thirteen minutes after Apple's filing, Samsung countered with a filing accusing the Cupertino, California-based company of trying "to stifle legitimate competition and limit consumer choice to maintain its historically exorbitant profits."

It said Apple should pay for using patented Samsung technology, "without which Apple could not have become a successful participant in the mobile telecommunications industry."

The dispute is part of a worldwide legal battle over the alleged theft of technology used in smartphones and tablets, including those powered by Google Inc's Android, which Samsung uses in its most popular devices.

In its filing, Apple claimed it is entitled to reasonable royalty rates equal to more than $31 per unit.

This includes $24 for use of Apple's "design patents or trade dress rights," $3.10 for a patent related to "scrolling" technology, $2.02 for a patent covering a "tap to zoom" feature, and $2.02 for a patent that tells users with a "bounce" when they reached the bottom of screens.

Apple also said that any remedy to which Samsung could be entitled over its "declared-essential patents" is limited to one-half of one cent per unit for each infringed patent.

Last week, Apple Chief Executive Tim Cook and top Samsung executives participated in court-supervised mediation to try to resolve the case but a resolution appeared to be unlikely, people familiar with the matter said.

The companies also disagreed on the value of the disputed patents, one of the people said.

In afternoon trading, Apple shares fell 69 cents to $603.14 on the Nasdaq. The company is expected to report quarterly results after the market closes.

The case is Apple Inc v. Samsung Electronics Co et al, U.S. District, Northern District of California, No. 11-01846.

(Reporting By Jonathan Stempel in New York; Additional reporting by Dan Levine in San Francisco; Editing by Maureen Bavdek and Andrew Hay)

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