Leasing activity in Manhattan in the first half of the year totaled 17.6 million square feet, the best six-month performance in 13 years and a 40% surge from the corresponding period of 2010, according to Cushman & Wakefield Inc. Meanwhile, activity in the last two months of the quarter was the strongest on record.

In yet another bullish sign, absorption—which measures the net change of occupied space in a given time—was a positive 3.2 million square feet. That marked the first time that measure has been positive for the first six months of the year since 2007.

“Leasing activity has been pretty impressive,” said Joseph Harbert, Cushman & Wakefield’s chief operating officer for he New York metro region.

All that activity helped shrink the overall average vacancy rate to 9.4% by the end of last month from 10.8% in the same period last year.

The surprising news for landlords—and the good news for tenants–was that despite the surge in deal volumes, the overall asking rents grew a mere 2% to an average of $55.52 a square foot.

“Increases are modest compared to the activity,” said Mr. Harbert. “This is still a relatively good [leasing] opportunity for tenants.”

Brokers at Cushman’s quarterly press briefing suggested several reasons for the disparity. One noted that the 9.4% vacancy rate still favors tenants and that once it hits 8%, which is widely considered a point where there is negotiating equilibrium between landlords and tenants, rents should shoot higher.

Another suggested some landlords were keeping quality space off the market, waiting for the market to further improve so they could fetch even richer numbers. Yet, a third suggested that the economy was still shaky enough where landlords didn’t want to quibble over price, especially not with credit-worthy tenants looking to lease significant blocks of space.

Some sub-markets in Manhattan are already seeing major increases. Mr. Harbert said rents in the Plaza District, the tony enclave favored by hedge funds and financial firms, were growing at twice the pace of the average, up 20% from the market trough.

Rents in the downtown market advanced more than in the other two business districts–midtown and midtown south. They jumped 4.2% to $39.38 a square foot. The market got a big boost from Condé Nast signing a 1 million square foot deal at 1 World Trade Center.

Source: Crain’s New York Business