Olympus E410 lenses (1 Viewer)

Hi all, i've been searching around for a 300mm lens for the Olympus E410, I was told in a photography shop near my work that sigma did a lens that would fit but im unsure after looking online.

I've read into this four thirds system but sigma dont seem to do a 75-300mm in a 4/3. Does anyone have any suggestions what other manufacturers other than sigma / olympus might sell a compatible 300mm lens? Im looking to spend about £150, I cant really afford the official olympus one!

Can anybody help?

There is an Olympus (Zuiko Digital) 70-300 mm 1/4-5.6. But the price on amazon for a new one is about £260, as you can see here:
http://www.amazon.co.uk/Olympus-ZUI...1?ie=UTF8&s=electronics&qid=1288693736&sr=8-1
Maybe you'll find an used one...