Qualcomm prevented Samsung Electronics, its biggest client for Snapdragon chip-sets, from selling its own Exynos counterpart to third-parties, South Korea's Fair Trade Commission claimed.
The commission said Samsung was prevented from selling its own mobile chip-set to other vendors besides its own through a patent licensing deal with Qualcomm.
The US chip giant's patents fall under standard essential patents that must be licensed in fair terms, according to the trade watchdog, which announced an $865 million fine against Qualcomm in December for patent abuse. It has ordered the company to change its terms.
Qualcomm has appealed against the decision and last month filed suit to an administrative court asking a reversal of the decision.
The original deal between the two companies was signed back in 1993 and allowed Samsung to make handsets with second-generation CDMA patents. It permitted the firm to make modem-chips for itself, but not others.
In 2011, when chip-sets began to package modems, graphic processing units, and application processors together, the South Korean tech giant requested a change to the contract.
But Qualcomm said buyers of Samsung's chip-set must pay it licensing fees or the latter must take the burden of pay, to which Samsung agreed. Later, Qualcomm said it would not file suit for only 60 days. The talks broke down in 2013.
Samsung uses both Qualcomm's Snapdragon chip-set and its own Exynos line-up for its Galaxy smartphone.
The South Korean company is the biggest buyer of the US giant's chips. It is also a contract maker for the chips.
The upcoming Galaxy S8 will be powered by Snapdragon 835 and Exynos 9, which uses the 10-nanomter production process.