(Bloomberg News) -- UBS had a good thing going in Puerto Rico. The Swiss bank served as an adviser to the commonwealth's Employees Retirement System, led the underwriting of a $2.9 billion bond issue for the pension agency in 2008, and then stuffed half of those bonds into a family of closed-end mutual funds it sold exclusively to customers on the island. It collected fees at every step.

Now, with the U.S. territory in the downward spiral of a government debt crisis, it's all coming apart for UBS, long the biggest retail brokerage on the island. After UBS helped the government dig itself into a deeper hole and put island customers on the hook for the losses that followed, its Puerto Rico saga has become a cautionary tale of how risks can multiply.

Subscribe Now

Access to premium content including in-depth coverage of mutual funds, hedge funds, 401(K)s, 529 plans, and more.

3-Week Free Trial

Insight and analysis into the management, marketing, operations and technology of the asset management industry.