"AOL Time Warner Inc. insisted on a contract provision that would allow it to pursue a takeover of Amazon.com Inc. as part of its agreement to invest $100 million in the giant Internet retailer."
So why did AOL invest in Amazon only to get 2% of their capital? Maybe they think the stock is still too expensive, and plan to increase their participation (in case Amazon needs more cash in the future). Or they wanted to take the pulse of the market on this deal before committing more money.
Update: Microsoft’s stake in the AOL-Amazon deal (it’s from CNet, that explains the misleading headline).