25.5.1 The Contract should require that all insurances are placed through a reputable insurer of good standing. In practice, financiers will ensure that insurances will be arranged by, and placed with brokers and insurers approved by them (or that fall within a particular category) and on terms acceptable to them.
25.5.2 There is usually no need to limit the market within which the Contractor must insure the relevant risks (e.g. the worldwide market is not unusual).
Suitable drafting is as follows:
The insurances referred to in this Clause shall be effected with insurers approved by the Authority, such approval not to be unreasonably withheld or delayed.