Mitsui Fudosan, the world's largest property owner by value, plans to expand its presence in Europe by initially targeting London's strong real estate market as part of a 500 billion yen ($6.14 billion) global expansion.

The Tokyo-based company, which holds about $30 billion in assets, with an additional $20 billion in an investment fund, plans to buy development parcels in the U.K. for new development, along with existing offices and shopping centers, Hideto Yamada, head of Mitsui’s European operations, told the Financial Times.

Eventually, Mitsui plans to expand to France, Germany and Spain, but it may delay growth because of the euro zone crisis. Eventually, properties outside of Japan could account for a third of its revenue, Yamada said.

“It is something we are going to do, but we will be opportunity-driven, and we don’t have specific targets in terms of timing and total investment. It is about finding the right partners in the right places and getting the opportunities when things come up,” Yamada said.

Mitsui also plans to launch a property fund management arm in hopes of attracting investments from Japanese pension and insurance groups. The company's U.K. arm also has a 15 percent stake in British developer Stanhope PLC.

London's office market is among the world's strongest. In 2011, vacant space in London's central market fell to 16.8 million square feet, down from 15.3 million square feet in 2010 and 23 million square feet in 2009, according to commercial real estate brokerage Knight Frank. Technology firms including Apple Inc. (NYSE: AAPL), Google (Nasdaq: GOOG) and Facebook leased office space in 2011.

Prime rents in London's West End neighborhood were up 8.8 percent in 2011 to £92.50 ($146.5) per square foot, making it one of the most expensive real estate markets in the road.

“Ten years ago, the investment market was dominated by U.K. investors, with a minority of foreign money mostly from the U.S. and Germany, said Stephen Clifton, an investment partner with Knight Frank, in a February statement. Now foreign capital from across the globe is the majority, with much of the investment coming from emerging markets and the mineral economies. Up until now the overseas money has targeted trophy assets, but I expect them to diversify their portfolios this year [by] taking on more risk, either buying sites or joint venturing with U.K. developers.

Mitsui also has holdings in the U.S. In January, it bought an 80 percent stake in the Homer Building, a 422,000-square-foot office just blocks from the White House, for $252 million.

Mitsui Fudosan was founded in 1673 by Mitsui Takatoshi, who began the company as a single retail store.