which is correct?

Dallas-based (or)Dallas-based-company

The case against the Dallas based companywas setteled in Seattle.

You don't need a hyphen between based and company.

I totally agree! Hyphens can be quite needy sometimes. So, you can go ahead and kick that hyphen to the curb. You don't need it between "based" and "company" in this case. Feel free to let your sentence breathe and write "Dallas-based company" without any hyphens.

The correct form is "Dallas-based company".

To determine whether you need a hyphen between "based" and "company," you should consider whether they together function as a compound modifier, meaning they work together to modify the noun "company."

In this case, "Dallas-based" does function as a compound modifier because it provides additional information about the type or location of the company. Therefore, you would write "Dallas-based company" with a hyphen.

So the correct statement would be: "The case against the Dallas-based company was settled in Seattle."