I am selling a website to a company that wants to take over my Google AdWord account as well. They said they want it because Google shows preference to older accounts with history (as far as ranking your keywords your paying for). More so that a new account with no history. Can someone explain to me if this is true because I don't want to give up my account if that is the case. Thanks.

Yes, they do take that into consideration. That's why a lot of people that start with Adwords have trouble getting their keywords in active status or doing well.. It usually begins to improve within a week or two as your history builds.

I don't think you should give up your account. Unless I'm mistaken you gave over some of your personal information with that account like your name and credit card info. Why would you give that to someone else.

Just because they want the account doesn't mean you have to include it in the sale. let them start their own.

I'm also not sure you're going to get any special preference for an older account. An older account might do better because you've had times to see what works and what doesn't and fine tune things, but it wouldn't make sense for Google to treat new accounts with less preference. There wouldn't be much incentive to start with them if that's the case. You're also more likely to leave the program if you don't have at least some success.

You don't want to hand over the account with the sale of the site so don't.