South Korea's top striker Park Ji-Sung of English Premier League club Manchester United has signed a long-term contract with sportswear company Nike that extends their commercial relationship until 2019. "Park merits our sponsorship in light of his achievement and influence in the world of football," a spokeswoman for Nike Sports Korea told AFP. The company did not reveal the value of the deal but sports dailies here said it was believed to be worth more than US$12 million.