Assets on the market total more than 19 million sf and include some buildings in core markets. "The sales market has just strengthened, and it's an excellent time to accelerate that process," Kincaid said during the company's earnings conference call. "It will be a challenge to do that much, but we're going to try."

Average occupancy on the properties sold this year have been in the 75% range, Kincaid said, but has been as low as 18%. "If we sell the assets we're attempting to sell, we'll be a much stronger company." He said occupancy across the REIT's portfolio, which now totals 124.5 million sf, would increase two percentage points as a result of the non-core market sales.

In addition to becoming buyers in its core markets, Equity Office Properties' options for redeploying the sales proceeds include paying off $1.1 billion in debt maturing this year that carries an average rate of 7.5% or buying back company stock. The company's board of directors has approved up to $500 million in stock buybacks. "Our first preference would be to buy new buildings," chief financial officer Marsha C. Williams said.