un·der·writ·er 
(ŭndər-rī′tər)
(ŭndər-rī′tər)n.
One that underwrites, especially:
a. A person or firm engaged in the insurance business.
b. An insurance agent who assesses the risk of enrolling an applicant for coverage or a policy.
c. One that guarantees the purchase of a full issue of stocks or bonds.
d. A sponsor, as of a television show.