(CNN) -- The share price of Samsung Electronics dropped nearly 7.5% in trading Monday as investors had their first opportunity to react to the more than $1 billion decision against the Korean electronics giant by a California jury for infringing on Apple patents.
Samsung dropped 6.3% at the open of South Korea's Kospi index and finished the day down 7.45%, after dropping as much as 7.7%. The tumble erased about $12 billion from the company's market value Monday.
Samsung is planning to appeal Friday's decision of a U.S. federal jury which awarded Apple $1.05 billion for copying the look and feel of iPhones and iPad design. The jury rejected Samsung's counterclaims against Apple.
A senior Samsung executive told the Korea Times the decision was "absolutely the worst scenario for us" as he was heading into an emergency meeting at the company's Seoul headquarters on Sunday.
The decision could lead to the prohibition of sales in the U.S. of Samsung smarphones and computer tablets found to have violated Apple's patents. A hearing on the matter is scheduled for September 20.
"As far as the money damages are concerned, (Samsung) will make that up in the long run. The bigger issue at the moment them having to come up with new and unique designs appealing to the customer base," said Christopher Carani, chairman of the design rights committee of the American Bar Association.
"It will lead to fewer choices, less innovation, and potentially higher prices," Samsung said in a written statement after Friday's decision. "It is unfortunate that patent law can be manipulated to give one company a monopoly over rectangles with rounded corners, or technology that is being improved every day by Samsung and other companies."
Apple, meanwhile, praised the court for "sending a loud and clear message that stealing isn't right."
"The mountain of evidence presented during the trial showed that Samsung's copying went far deeper than even we knew," the company said in a statement.
A nine-person jury spent just two and a half days puzzling out its final verdict, with weeks of notes and memories of testimony, 109 pages of jury instructions, and boxes of evidence including a collection of contested smartphones and tablets as their guide.
The jury award shows the growing importance of design for electronics makers. In 2001, Apple and Samsung were awarded 10 and eight U.S. design patents, respectively. This year, Apple could have as many as 333 design patents approved, while Samsung could have as many as 500, Carani said.
"Central to the U.S. case and at its very core was design rights, the way things look, and that's really where the large amount of this billion-dollar damages judgment comes from," Carani said.
The lawsuit is the largest yet in the ongoing worldwide patent brawl between the two companies, which itself is just one battle in Apple's war against Google's Android mobile operating system. On Friday, a South Korean court found that both parties had infringed on each other's patents, banning the sale of the iPhone 3GS, iPhone 4, two iPad models and Samsung's Galaxy S2.
The Korean court ordered Apple to pay Samsung $35,000 and Samsung to pay Apple $22,000.
CNN's Paula Hancocks, Heather Kelly, John D. Sutter and Dan Simon contributed to this report