mutualize

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To make mutual.
• intransitive verb To set up or reorganize (a corporation) so that the majority of common stock is owned by customers or employees.
• intransitive verb To become mutual.

from The Century Dictionary.

• To render mutual; specifically, reorganize (a proprietary or stock insurance company) as a mutual company. See mutual, 4.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb To make, or to become mutual
• verb To organize a business (especially a financial business) so that it is owned by its customers (or its employees)