How Can create one service contract line for group od OM sales order product

I create Sales order with 3 products (all of then Installed base tracable and service contract enable)

I add service item for each of those lines some service item and same period

After shipping the service contract was created with 3 service lines and for each line I have one subline, all line are with the same service item and same period.

What I need is to have one service contract with one line and 3 sublines

Example :

OM

line1 item prod-A with service line service-A

line2 item prod-B with service line service-A

line3 item prod-C with service line service-A

I got service contract as :