OSO Processing

I am looking for a stock broker that offers OSO(Order Submits
Order) order processing.

The only broker I have found is MYTRACK.

Any help would be appreciated.

 

I think TradeStation will do this.

 

are you describing

http://www.interactivebrokers.com/php/webhelp/Making_Trades/Create_Order_Types/conditional.htm

here?

 

Apparently, TradeKing has Order Triggers Orders (i.e. more than 1 order). IB has Order Triggers one Order. However, quite a few brokers have conditional orders (e.g., IB, Ameritrade, etc.) which you might tinker to make it work closely like Order Triggers (multiple) Orders.