Admerasia http://www.admerasia.com/ (based in NY) I think they have a strong media planning team. They didn't show their creative work on the website, so not sure about that.
Kang & Lee http://www.kanglee.com/ (based in NY) According to the billing record, they are the largest one.
Ameredia http://www.ameredia.com (based in SF)
interTREND Communications http://www.intertrend.com/ (based in Long Beach) Toyota
PanCom International http://www.pancom.com/ (based in LA) looks like SBC, Ford and Volvo are their big clients.