RPC__E_DISCONNECTED error(0x80010108) while calling a callback aftre 6 mins

I have an issue with my COM application. The Call sequence is as follows.

COM client(STA) calls GetData() of a COM dll passing a callback pointer. GetData() has a while loop which takes a long time(more than 6 minutes) COM dll Marshalls the interface and it creates a thread. The thread enters an MTA and unmarshalles the call back pointer and calls OnGetData() of COM client. But when calling the callback function(OnGetData() ) the call doesn't reach the Client, instead I get RPC__E_DISCONNECTED error(0x80010108).

How can I solve this error? If its a normal scenario that it time outs in 6 minutes, is there any way to change the time out?