The initiative also involves Nayms, a crypto-compatible insurance marketplace, and Copper.co, a digital asset custodian.
In her expanded role at Lloyd’s, Miller will continue to lead the commercial directorate and remain a member of Lloyd’s executive committee.
Rory MacGregor, divisional head of non-marine, will be promoted to head of underwriting.
The new company is set to make its formal debut at the British Insurance Brokers’ Association conference, taking place on 15 to 16 May in Manchester.
Following the rebranding of its broking operations in October 2023, Howden aims to express its collective expertise in the reinsurance business through a single identity.
The consortium will initially offer a maximum line of US$40 million, led by Antares with a 75 per cent share.
Global reinsurer capital increased by 17 per cent to US$670 billion in 2023.
Geddes’s former role as head of property and allied lines for MS Amlin will be filled internally by Simon Morgan.
