The availability of sublease space in the US office market appears to have peaked, with the market reaching what Cushman & Wakefield economists say is an inflection point.

There was 130 million square feet of vacant sublease space as of the third quarter, a figure that translates into 13.4% of total vacant space in the US. That's also a decline of 2 million square feet over last quarter, a welcome decrease after seven straight quarters of increasing inventory.

"This timing would match a similar path to the previous two recessions when sublease space increased for approximately two years before hitting its highest point and then receding," Cushman analysts note in a recent report, and adding that vacant sublease space feel quarter-over-quarter in more than half of the 86 US markets they tracked. That includes 20 markets where sublease inventory dropped by more than 100,000 square feet.