Noreen, the Oxford English Dictionary spellings are mostly -ize. This has been standard since the start of their program in 1857.
My question stands.

Quoting from the OED:
1. Words that have come down from Greek, or adopted from Greek, or formed on Greek elements. Examples- canonize, christianize, crystallize, etc. etc.
2. Words formed on Latin adjectives and substantives- civilize, colonize, brutalize, nationalize, etc. etc.
3. Words from later sources- jeopardize, womanize, cricketize, etc. etc.
4. Words formed from ethnic adjectives- Anglicize, Americanize, Latinize, etc.
5. Words formed on names of persons- Calvinize, Bowdlerize, macadamize, Merry-Andrewise, ec. etc.
6. Words from the names of substances and processes- oxidize, carbonize, hydrogenize, etc, etc.
Colonization, civilization and other nouns that fit the above categories.

So- changing a line from the comedy of Eliza Doolittle and her mentor, Why can't the English- learn to spell?

The suffix -ise.
"A frequent spelling of -IZE, suffix forming vbs, which see."
Used with abstract substantives of quality, state, function.