AXA S.A., one of the world’s largest financial services companies, has agreed to pay the equivalent of about $10.3 billion in cash for the Winterthur Group, a large European insurer.

Executives at AXA, Paris, say the company is buying Winterthur, which is based in Winterthur, Switzerland, from its current owner, Credit Suisse Group, Zurich, to gain market share.

“This transaction is a unique opportunity to reinforce our leading position in our core European market and to increase our presence in high growth markets, notably in Central and Eastern Europe and in Asia,” Henri de Castries, AXA’s chief executive, says in a statement about the deal.

In addition to paying $10.3 billion for Winterthur, AXA plans to refinance about $1.3 billion of Winterthur’s outstanding debt.

AXA hopes to receive the European antitrust approvals and other regulatory approvals it needs to complete the deal by the end of the year, the company says.

Winterthur gets about 62% of its business from life and savings operations and 38% from sales of property-casualty insurance products and services, according to company figures.

Winterthur has large operations in Belgium, Germany, the Netherlands, Spain, Switzerland and the United Kingdom as well as in markets such as China, the Czech Republic, Hong Kong, Hungary, Japan, Poland and Slovakia.

AXA is estimating that it will spend about $660 million to restructure Winterthur, but it says it plans to keep the current management of many of Winterthur’s operations, such as the company’s asset-management operations.

AXA says it expects to raise almost half of the cash it needs to pay for Winterthur by selling stock and to get the rest by issuing a mix of senior debt, subordinated debt and perpetual deeply subordinated debt.