(Bloomberg) — Endurance Specialty Holdings Ltd. began an exchange offer for shares of Aspen Insurance Holdings Ltd. as part of a $3.2 billion effort to acquire the insurer.

The offer begins today and expires at 5 p.m. New York time on Aug. 29, Bermuda-based Endurance said today in a statement.

Copyright 2018 Bloomberg. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.