British insurer Aviva plc is seeking bidders for its Aviva USA unit in a move that analysts say would allow it to divest an underperforming annuities operation so it can focus on its Europe businesses.

Aviva CEO Andrew Moss recently told an investor conference that the company would be open to offers for its American unit, Reuters reported Thursday. However, investment bankers said the company may struggle to sell its American operations, estimated to be worth approximately $1.6 billion, due in part to a tough regulatory environment.

Based in West Des Moines, Aviva USA was formed when Aviva acquired AmerUs Group Co. in 2005.

Aviva USA’s CEO has sent a letter to agents assuring them that if a decision to sell is reached, “you will hear it from us directly rather than just read about it in the papers,” The Des Moines Register reported.

Bankers said potential European buyers could be put off from bidding because of new European insurance rules due to come into force, the so-called Solvency II capital directive.

“That leaves North American buyers like Prudential Financial and MetLife, and there is no guarantee they would want to buy as opposed to just writing more new business of their own,” said one banker.

A second banker added there was a slim chance a Japanese insurer might take a look, but only if it were very keen to enter the U.S. market, since some large Asian insurers have recently bulked up in the region.

Shore Capital Group plc analyst Eamonn Flanagan said that if Aviva did manage to sell Aviva USA, it would be well received by its shareholders because the business has underperformed in relation to its domestic rivals.

The AmerUs acquisition was made under previous CEO Richard Harvey at a cost of around 2 billion pounds, including debt, and was part of a plan for the company to expand globally. Moss has been refocusing Aviva around the United Kingdom and Europe.