June 12 (Bloomberg) -- Brookfield Asset Management Inc., North America's biggest publicly traded property manager, agreed to buy Multiplex Group for A$4.2 billion ($3.5 billion) as banks and commodities producers in Australia boost demand for offices.

The cash bid values Multiplex, builder of London's Wembley Stadium, at A$5.05 a share, 22 percent more than the stock was trading at before a takeover approach was announced. The offer is supported by the founding Roberts family, holders of a 25.6 percent stake, Sydney-based Multiplex said in a statement today.

The purchase will raise Toronto-based Brookfield's property portfolio by $7 billion to $33 billion, adding buildings in Australia's four largest cities, and give it a construction business spanning Australia, Britain and the Middle East. Lawsuits and regulatory probes into Wembley have marred Multiplex's three years as a listed company.

``Multiplex has had some very well-publicized problems, which have put a lid on the share price, and Brookfield has obviously seen an opportunity'' said John Snowden, who oversees the equivalent of $6.7 billion in property securities at Colonial First State in Sydney, including Multiplex shares. ``Demand for office space in Australia has been very strong.''

About 52 percent of Multiplex's properties are in Sydney and about 20 percent are in Melbourne. Its office buildings include the 867,032-square-foot Southern Cross in Melbourne and a 50 percent stake in the 423,656-square-foot Bank West Tower in Perth, Australia.

Multiplex shares rose 3 cents to A$5.03 at 11:19 a.m. in Sydney.

Existing Investment

Brookfield, which has an existing investment of $145 million in Multiplex, said yesterday it will finance the bid with $1.9 billion in cash and a $1.5 billion loan. The total value of the deal, including debt, is about A$7.3 billion.

More than 60 percent of Multiplex's construction business is in Australia and New Zealand, 30 percent is in the Middle East and 8 percent is in the United Kingdom. It also has a fund- management business with $6.13 billion under management, including more than $3 billion of third-party assets.

Brookfield has announced at least eight acquisitions in the past year as the company seeks to buy assets that generate recurring management fees such as infrastructure, buildings and timberlands.

Multiplex is the company's first purchase in Australia. In April, Brookfield completed the $1.63 billion cash acquisition of Longview Fibre Co., making it one of the five largest owners of private timberlands in North America.

The office vacancy rate in the Asia-Pacific region fell 0.42 percentage point to an average 7.65 percent in the second half of last year, according to Colliers International.

Multiplex said in February that Chief Executive Officer Andrew Roberts and his family may make a takeover bid with Brookfield Asset Management. The Roberts family has no involvement in the offer, Multiplex said today.

Wembley Struggles

Multiplex's redevelopment of Wembley had been more than a year overdue. Multiplex handed control of the stadium to the owners, England's Football Association, in March. It is the world's most expensive sports venue at 757 million pounds ($1.49 billion).

Multiplex has been run by Managing Directors Bob McKinnon and Ross McDiven since Roberts stepped aside Feb. 5 to avoid a conflict of interest during the buyout discussions.

The Roberts family listed Multiplex on the Australian Stock Exchange in December 2003, raising A$901 million in the share sale. The company was founded by John Roberts, father of Andrew, Tim and Denby, in 1962 in Perth. Roberts stepped down as executive chairman in 2005 after the Wembley losses. He died in June of last year.

Brookfield, which manages about $70 billion of assets, receives the biggest portion of earnings from property leasing. It holds 50 percent of Brookfield Properties Corp., owner of Manhattan's World Financial Center.

In January, Brookfield offered to buy shopping-mall owner Mills Corp. for $1.35 billion. A month later, Chevy Chase, Maryland-based Mills agreed to be acquired by Simon Property Group Inc. and Farallon Capital Management LLC, which topped Brookfield's bid with a $1.64 billion offer.

To contact the reporters on this story: Daniel Taub in Los Angeles at dtaub@bloomberg.net; Fergus Maguire in Canberra, Australia at fmaguire@bloomberg.net

Last Updated: June 11, 2007 21:27 EDT