HP has settled its lawsuit against three printer cartridge refill vendors accused of patent violation. 

HP filed the original complaint last November in a Düsseldorf district court. 

The company alleged that German firm InkTec GmbH and its parent company InkTec Ltd of Korea had used ink in its refill kits that violated two of HP's patents on ink formulas. 

A third German company, PCE Group, also sold the InkTec kits and was included in the settlement.

All three companies admitted to infringing on HP's patents. They will pay HP an undisclosed sum and will be barred from selling the offending kits. The companies will also be pulling any offending kits currently on the market.

Michael Hoffman, senior vice president of HP's supplies, imaging and printing group, said: "We are pleased to have resolved this matter quickly without extensive litigation and will continue to monitor InkTec and others for possible patent infringement as part of our ongoing worldwide testing and enforcement efforts."