Looking into Pronunciation of double consonants, turned up an apparent rule for pronouncing a double-C in English that seems to parallel the Italian rule for pronouncing a single C. If the "cc" is followed by a bright vowel ("i" or "e"), it is pronounced /ks/:
accent, occipital, eccentric
Otherwise it is pronounced /k/:
account, occasion, occupy
A dictionary search throws up a few exceptions to this, which mostly appear to be musical loan words from Italian which are still pronounced as the in original ("acciaccatura" for example).
The question is this: how did this rule come about? The parallel with Italian is close enough to make me very suspicious, but I haven't been able to prove a connection between the two.