(Bloomberg News) ProLogis and AMB Property Corp. shareholders today approved a merger of the industrial landlords as demand for warehouse space rises amid a strengthening global economy.

The combination of the two biggest U.S. industrial real estate investment trusts will result in a company with $46 billion in assets. The REITs expect about $80 million in annual general and administrative savings from the merger, according to a Jan. 31 statement announcing the transaction.

Cost cuts will help the merged company amid an economic expansion that has sent the Standard & Poor's 500 Index up 5.6 percent this year and Europe's Stoxx 600 up 0.9 percent. In the U.S., industrial-property vacancies are falling, indicating rising demand for warehouse space as manufacturing increases, real estate broker Cushman & Wakefield Inc. said May 24.

"It was a very opportunistic deal for AMB to expand their geographic presence and better utilize their underlying infrastructure," Dave Rodgers, an analyst at RBC Capital Markets in Solon, Ohio, said before the results of the shareholder vote were announced. "It's a deal that puts them in a very strong competitive position throughout the world."

The company, which will be the world's biggest warehouse REIT, will take the ProLogis name and have its corporate headquarters in San Francisco, where AMB is based. AMB Chief Executive Officer Hamid Moghadam and Walter Rakowich, who holds the same position at ProLogis, will be co-CEOs through 2012, when Rakowich will retire and Moghadam will become sole CEO.

Support For Merger

ProLogis, based in Denver, said that holders of more than 498 million of the company's outstanding shares, or 87.4 percent, voted and 99.6 percent of those supported the transaction. More than 154.2 million of AMB's shares, or 89.6 percent, were voted, with 98.5 percent backing the agreement. The merger is scheduled for completion June 3, ProLogis said.

The combined company will own or manage properties in 22 countries. The real estate is valued at $28 billion in the Americas, $13 billion in Europe and $5 billion in Asia, according to a proxy statement filed with the U.S. Securities and Exchange Commission on May 2.

ProLogis fell 35 cents, or 2.1 percent, to $16.21 as of 12:39 p.m. in New York Stock Exchange composite trading. The shares have gained 50 percent in the past year, compared with a 43 percent increase in the Bloomberg REIT Industrial/Warehouse Index.

AMB fell 68 cents, or 1.8 percent, to $36.31.