manageable
noticeable
peaceable
pledgeable
serviceable
Words ending in double ee retain both letters, as—agreeable.
In words of English formation, a final consonant is usually doubled before -able, as—
admittable
biddable
clubbable
conferrable
deferrable
forgettable
gettable
incurrable
rebuttable
regrettable[2]
FOOTNOTES:
[1] At Oxford especially, it must always be remembered that the Bible has a spelling of its own; and that in Bible and Prayer Book printing the Oxford standards are to be exactly followed.—H. H.
[2] For an authoritative statement on the whole subject see The Oxford Dictionary, Vol. I, p. 910, art. -ble.