The U.S. Supreme Court has agreed to hear a case in which Microsoft is defending itself against software development firm i4i over a $290 million patent infringement judgement. The case is expected to be heard by the Supreme Court next spring.

i4i sued Microsoft alleging that the Washington tech giant's Word software included an XML editing feature that violated one of its patents. In 2009, courts ruled in favor of i4i and ordered Microsoft to pay the Canadian firm for damages. Microsoft ultimately appealed the ruling, which will now be heard by the Supreme Court.

Meanwhile, several large corporations - including Google, Apple, Toyota and Wal-Mart - have sided with Microsoft, likely agreeing with company spokesman Kevin Kutz's assertion that the "case is certainly about protecting innovation. Innovation is harmed by bad patents. When bad patents can't be challenged effectively, that's when innovation is significantly at risk."

However, 141 companies signed a letter last week to the U.S. Department of Justice, arguing that a reversal of the decision would be disastrous for the country's systems of patent, trademark and intellectual property enforcement, according to the Seattle Times.

"We are greatly concerned that a reversal of the lower court's decision in this case could seriously weaken the presumption of validity that attaches to millions of patents in force in the United States today," the letter reads, "thereby undermining long-standing investment-backed reliance interests that are critical for domestic job creation and economic growth, and for U.S. technological leadership internationally."