Italy's competition authority has fined Apple and Samsung €15 million ($26.2m) after claims the companies deliberately slow down their phones to force users to upgrade.
The tech firms received the maximum fine possible in the first ruling of its kind against smartphone manufacturers in Europe following complex investigations by the country's antitrust watchdog.
A similar probe was launched in France earlier this year.
The investigations followed accusations worldwide that both companies encourage system updates that slow older phones and make them obsolete.
Apple and Samsung were fined €10m and €5m apiece following investigations that determined they held "unfair commercial practices".