Blackberry maker Research in Motion (RIM) has been ordered to pay $147m in damages after losing a patents case.
A jury in San Francisco upheld claims by Mformation Technologies Inc that RIM infringed patents it took out in 1999.
The software involved allows companies to access employees' mobile phones remotely for upgrades, password changes or to delete data.
The fine was calculated by the judge as $8 per Blackberry device in use since the claims were first filed in 2008.
"We believe [the patents have] been fundamental to the success of Research in Motion," said Amar Thakur, a lawyer for the winning side.
The damages only relate to royalties on past sales in the US, and does not cover future sales or sales outside the US.
"Mformation created the mobile device management category in the late 1990s and was innovating in this area well before most of the market understood the fundamental importance of wireless mobility management," said the firm's founder Rakesh Kushwaha in a press release .
The case adds to RIM's problems. Since the introduction of Apple's iPhone in 2007, sales in the Canadian firm's core Western market have been steadily declining.
The company is cutting 5,000 jobs - almost a third of its workforce.
RIM said in a press release that it was: "disappointed by the outcome and is evaluating all legal options.
"Additionally, the trial judge has yet to decide certain legal issues that might impact the verdict. RIM will await those rulings before deciding whether to pursue an appeal."