IBM Corp. of Armonk, NY, controls 25 million square feet around the globe while locally headquartered Sun Microsystems controls approximately 12.8 million square feet. Most both companies' portfolios are in the US--IBM's being weighted toward the East Coast and Sun's toward the West. IBM owns most of its facilities while Sun Microsystems leases most of its space.

The two companies' real estate portfolios became of more interest this week with news that the two are in merger talks. IBM reportedly offered $6.5 billion cash for Sun, according to multiple reports. The news sent shares of Sun up and shares of IBM down. In late afternoon trading, shares of IBM were trading at $92.20, of f $0.71 on the day while Sun shares shot up to $8.96, up $3.99 (80%) on the day.

Sun has a market cap of $4 billion and its last quarterly report shows it with upward of $2.6 billion in cash and securities. IBM has a market cap of $123 billion and nearly $13 billion in cash.

As of the start of the year, IBM had aggregate floor space of 19 million square feet, of which 15 million square feet was owned and 4 million square feet was leased. Of that total, 2 million square feet was vacant and 1 million square feet was being leased to non-IBM businesses. The company controls another 6 million square feet internationally, two-thirds of it leased, one third of it owned and sixth of it leased to non-IBM businesses.

Sun Microsystems controls 8.2 million square feet in the US and 4.6 million square feet internationally. About three quarters of the total, or 8.8 million square feet, is leased, with 5.2 million square feet leased in the US and 3.6 million square feet leased internationally. In 2008, Sun reduced its owned square footage by 3.8 million square feet via sale-leaseback transactions for properties in Lousiville, CO; Newark, CA; and Burlington, MA.

IBM does not break down the size and location of its facilities in its annual report. Sun breaks down its owned facilities in its report, showing nearly 2 million square feet of owned space in the Bay Area cities of Santa Clara and Menlo Park, just over 1 million square feet in Broomfield, CO and 400,000 square feet each in Farnborough, England and Linlithgow, Scotland.