The EU has slapped the world's largest generic drugmaker Teva with a $502 million fine for "abusing its dominant position" to impede competition for its blockbuster multiple sclerosis medicine.

The Israeli company said on Thursday it would appeal against the EU's fine.

The European Commission, the EU's antitrust watchdog, said it found Teva "artificially extended the patent protection" of its drug Copaxone and "systematically spread misleading information about a competing product to hinder its market entry and uptake".

The EU said Teva had abused its dominant position in the medicine for multiple sclerosis in Belgium, Czechia, Germany, Italy, The Netherlands, Poland and Spain.

"Today's decision to impose an antitrust fine on Teva for disparagement and misuse of the patent system reaffirms the commission's commitment to competition enforcement in the pharmaceutical sector," EU competition chief Margrethe Vestager said.

The EU's move "contributes to keeping drugs affordable, preserving choice of treatment and fostering innovation, to the benefit of EU patients and national healthcare systems", she added.

The Israel-based company said it was "deeply disappointed" by the EU's fine and would "vigorously defend its position on appeal".

"Teva disagrees with the commission's legal theories which are legally untested and, Teva believes, not supported by the facts," it said in a statement.

It is not Teva's first EU fine.

EU regulators in 2020 fined the company and drug-maker Cephalon –– which Teva later bought –– for colluding to delay a cheaper generic version of a sleep disorder drug.

Teva also challenged that fine and its appeal continues.