Aviva plc announced today that it has agreed to sell West Des Moines-based Aviva USA Corp. to Athene Holding Ltd for $1.8 billion.

The deal will make Aviva USA – which will be renamed Athene USA – the parent company of Athene’s U.S. operations, and the company will remain headquartered in West Des Moines. A company press release said Athene is committed to “retaining a substantial employee base in Des Moines as the centerpiece of Athene USA’s nationwide operations.”

The transaction is expected to close in 2013, and is subject to regulatory approval.

Athene said the West Des Moines operations would combine with Delaware-based Athene Annuity & Life Assurance Co. to form the second-largest issuer of fixed indexed annuities in the United States.

Aviva plc said that the transaction represents progress in narrowing its focus on businesses and markets where Aviva can be a leader.

Aviva will retain the North American asset management activities of Aviva Investors that are focused on third parties, and Aviva plc assets outside of the United States.

Aviva plc built a $135 million headquarters in 2010 in West Des Moines.