I'm not sure if this is an IT issue or a customer service failure but after a very short hold with the Finnair call centre my conversation went basically like this:

I hope you can help me ticket a multisector itinerary that I can't book online. I have done some research and know what flights I need.

Can you give me the departure and arrival cities and dates?

Its a Sydney to Los Angeles return but there are 4 segments each way and some long layovers/stopovers in Helsinki so shall I give you each segment separately?

No give me the departure and return dates

OK leaving Sydney on Sept 30 and returning from Los Angeles on December 10 in Business Class

On September 30th SYD-LAX the flight is on United Airlines

The itinerary that I have priced out online is a bit complex. Can I give you the flights I would like and if you can price it out I am ready to purchase.

Oh if you have a complicated itinerary we suggest that you book through a travel agent. You should go to something like Expedia.

I'm surprised. this is the first time an airline has told me that they can't book a trip through their own system.

Our system can't book complicated itineraries and you will need to book through a travel agent. Is there anything else I can help you with?

No, Thank you.