Aviamark, you actually have the option to do the FAA ATP if you meet the hour requirements
You DO NOT need a US CPL in order to apply for a US ATP.
You can use a foreign ATP or a foreign CPL as long as it is issued by an ICAO member state.
The regulation is 61.153(d)(3)
FAR Part 61 Sec. 61.153 effective as of 10/20/2009
3) Holds either a foreign airline transport pilot license with instrument privileges, or a foreign commercial pilot license with an instrument rating, that--
(i) Was issued by a contracting State to the Convention on International Civil Aviation; and
(ii) Contains no geographical limitations.(e) Meet the aeronautical experience requirements of this subpart that apply to the aircraft category and class rating sought before applying for the practical test
You do need to pass the one (1!) FAA written test
