The company assumed its current form when it sold its 90% of its Systems division (and original name) to entrepreneur Terry Matthews. Matthews took the division private under the original company name Mitel. Matthews had founded the company in 1973 with partner Michael Cowpland. They later lost control and were forced to sell their holdings in the company to British Telecom. In 2007, Zarlink divested itself of its remaining holdings in the Mitel systems business. Zarlink had retained 10% of the business with its sale to become Mitel. Zarlink exercised a put option from the original and sold its interest to Mitel.
The odd name is derived from the phrase Tsar of Links to reflect its interest in networking products.
In June 2005, it was removed from the S&P/TSX Composite Index. In June 2007 Zarlink acquired Legerity, producing voice integrated circiuts.