Russian champions Zenit St Petersburg signed much coveted Brazilian international striker Hulk from Portuguese giants Porto on a five-year contract on Monday, the buying club\'s official site announced. No financial details of the deal were disclosed, although it has been widely reported that an initial bid of 50 million euros ($63m) had been rejected before Zenit returned with another offer. The 26-year-old, who has won three Portuguese titles and the 2011 Europa League trophy with Porto since joining from the Japanese J League in 2008, has scored five goals in his 14 international appearances.