NEW YORK CITY-In announcing Thursday’s agreement withSilverstein Properties Inc. on a development plan for SPI’s threeWorld Trade Center towers, the Port Authority of New York and NewJersey noted that the deal followed other recent milestones atGround Zero. They include a joint venture with the DurstOrganization in which Durst will take a minority stake in thePort’s 1 World Trade Center, continued progress on building the1,776-foot tower and a letter of intent by Conde Nast to lease onemillion square feet there. Looking out beyond the WTC redevelopmentsite, the Alliance for Downtown New York would point to otherpositive signs in Lower Manhattan, including a surge in officeleasing.

“Downtown had a blockbuster month of leasing” in July, says themost recent MarketView Downtown Manhattan Snapshot from CB RichardEllis. The 620,000 square feet leased during July topped thefive-year monthly average by 63%, the first time in 11 months thatthis occurred, according to CBRE.

A major portion of the submarket’s July tally came from a singledeal: the 171,988-square-foot lease signed by Healthfirst at thelargely vacant 100 Church St. It was the first office tenant thatSL Green Realty Corp., which foreclosed on and then acquired 100Church earlier this year, had signed since launching arepositioning campaign at the 1.1-million-square-foot tower. Evenwithout the Healthfirst lease, though, Downtown’s leasing tally forJuly would still exceed the historical average for the month, CBREsays.