A spokeswoman for Oaktree confirmed by email that this is a newly created role.
Mr. Halagan is primarily responsible for "working with insurance clients globally and developing solutions for their balance sheet assets," said a Thursday release.
Based in New York, Mr. Halagan reports to Tony Harrington, managing director and global head of marketing and client relations.
Mr. Halagan was formerly at Mercer Investments where he served as partner and co-head of U.S. insurance investments across North America.
Oaktree had $172 billion in assets under management as of March 31, the release noted.
A spokeswoman for Mercer said by email that Chris Tschida has assumed the role of head of U.S. Insurance.