It all depends where the team sponsorship comes from, a national news paper could be the answer, someone like the Sun or Star, possibly a supplement company that is breaking into the market, and wants exposure to a new section of strength sport they might not have access to otherwise.
In terms of what can be offered, there would be the obvious product palcement on shirts, arm warmers, team bags, tracksuits, then every competitor could post about them on twitter, blogs, facebook etc. Banner ads on websites for clubs or BAF all sorts, but they must be shown to get value for money and lots of exposure, there are around 1000-1600 competitiors at worlds, not to mention any supporters, spectators, live streaming etc that could bring a huge new market for companies looking to break into different sectors of the sports market.