Coca-Cola already sponsors 'American Idol', which returns to Fox in the spring.
The 'American Idol' finale this year was watched by 23 million viewers across the US.
Fox is replacing 'American Idol' with America's version of 'The X Factor', which will air in the autumn and is expected to have Cowell on the judging panel.
Fellow judge Cheryl Cole and UK presenter Dermot O'Leary are rumoured to be joining Cowell on the US show.
The UK version of 'The X Factor' is sponsored by TalkTalk, in a three-year deal worth £20m.