[Steve]

I've been doing a search for retail suppliers of Edme's Maris Otter LME but all that seems to come up are forum topics discussing the product or the usual online sources for MO whole malt.  I also read that Crisp produces an LME (Crisp and EDME are malting sisters).  I emailed Crisp for a US distributor, but haven't heard back yet.

Does anyone have an online source for either MO LME?

[BrewingRover]

Edme doesn't export to the US anymore, as far as I know. You might try Munton's extract; it doesn't specify Maris Otter but it is English malt.
http://www.muntons.com/homebeer/other-products/canned_malt.asp

Northern Brewer has this and there are probably other places, too.

[Steve]

I emailed "Ask Linda" on the Munton's site to ask her if they use MO in any LME or for a retail source in the U.S.  I'll update when I hear back from Munton's.

I heard back from Crisp with no positive results.