During the first six months of the year, office market demand in Boston and Cambridge increased by the largest amount since the second half of 2007.

A total of  821,000 square feet of was absorbed in the first six months of 2012, according to an office market overview released Thursday by New York-based Newmark Grubb Knight Frank.

"While the market still has significant ground to make up in order to reach pre-recession conditions, the paradigm is shifting in many submarkets from a tenant-favored market to a landlord-favored market," the report said.

With demand exceeding supply and rents high enough to justify new construction, tenants are willing to pay premiums for brand new space, the study found. At Life Science Square in Cambridge, for example, Alexandria Real Estate Equities is building a 190,000-square-foot build-to-suit office building for Biogen Idec.

"As rents continue to rise across the market, this trend is expected to continue into the foreseeable future until the market again reaches equilibrium," the report said.

The firm predicts a continued increase in leasing activity in Boston’s Financial District during the second half of the year.

 "With the supply of available space quickly diminishing and some of the region’s highest asking rents in Fort Point/Seaport and Back Bay, activity in the Financial District is expected to amplify," the report said.