There are multiple definitions - click on the translation that matches your context.

assurandør

substantiv

full

underwriter

noun

Definitions of underwriter

English

an institutional investor who takes on the risk of a new share issue by agreeing to buy unsold shares

New shares not purchased will be taken up by the underwriter.

English

in the field of insurance, the person who guarantees the risk

The underwriters at the insurance company rely heavily on statistics to determine whether the company should insure the risk.