There are a few options out there that I can think of but none of them are specific LRF rods. The first couple I have myself.
Daiwa do 4 piece trout rods in their Presso Iprimi and previously in their Heartland series. Not sure what the current models are and I don't have the JDM catalogue here. Can let you know later. They are quite through action, not by any means soggy or floppy though.
There is a lighter Sage than the one Nick mentions. The one I have is 6ft 3 piece rated for 4-10lb line and lures up to 3/8oz. Mine has been all over and caught loads of fish, When I was in OZ it was my first LRF rod. I caught loads of bream and flathead using small SPs. The only downside is the 'old school build' with cork handle but that apart excellent. A great blank. I also have the same blank cutom build as a baitcaster. That is great fun!
Also check out the G Loomis Escape series, they do a 6ft 3in 3 piece which is quite highly regarded. There is a review on TackleTour somewhere.
Out of the three the Sage is the better LRF rod but none are 'true' (as in designed for) LRF rods. All of them will go in a suitcase too.
For something slightly heavier Daiwa do a 5 pieve Morethan lure rod. Not cheap at the moment wth exchange rates as they are.
I have quite a few travel rods and never go away without one!
That 'even lighter' Sage that you mention is the one that for some reason I never got,,,,,I think that they are utterly brilliant rods and complement the 'top end' saltwater fly rods brilliantly.
I am consistantly amazed that people dont seem to know about these rods and how good they are,I would rate my two as being as good as both my Tenryus for what they do.
Perfect for HRF/LRF ,if there was anything I could change it would be to have them as a two piece so I could carry them tackled up in the back of the car.
The cork handles dont bother me at all,,,,,,,,,,,Basically I love um and couldn't ever sell them.