Cornerstone buys European prop. investor Protego

* Purchase to lead to more expansion opportunities in Europe

* Cornerstone to manage $30 bln in assets after deals

LONDON, Nov 20 (Reuters) - U.S.-based Cornerstone Real Estate Advisers is acquiring European real estate investment firm Protego, opening up opportunities to invest in Europe's recovering property markets, the companies said on Friday.

After the deal completes in first-quarter 2010, Cornerstone, a unit of Massachusetts Mutual Life Insurance (MassMutual), will become one of the world's largest real estate managers with $30 billion in assets, they said.

UK-based Protego manages about $2.5 billion of property in the UK, Sweden, Finland and Germany. The financial terms of the acquisition were not disclosed.

"This new entity will better position Cornerstone and Protego ... to satisfy the increasing needs of our clients to provide a wide array of investment options," David Reilly, president and CEO of Cornerstone, said in a statement.

"We also believe that we will be best served at this time by maintaining the strong brand name of Protego in Europe," he said, adding the purchase will provide further expansion opportunities in Europe.

The deal follows a $250 million joint venture between Texas-based L&B Realty Advisors and Mayfair Capital Investment Management, formed in October to invest in commercial property in Britain on behalf of L&B's U.S. pension fund clients. [ID:nLM547057]

At the same time as the Protego acquisition, Cornerstone will integrate the Real Estate Finance Group (REFG) of Babson Capital Management, another MassMutual subsidiary, and become a subsidiary of Babson, the statement said.

REFG specialises in commercial mortgage lending and related products, and manages $21 billion in assets, it said. (Reporting by Daryl Loo; Editing by Andrew Macdonald) (See www.reutersrealestate.com for the global service for real estate professionals from Reuters)