Wilmington is not giving up control of the British Press Awards, the event long associated with the title.
The two companies have reached an agreement to collaborate on the Awards and other events.
According to Press Gazette's coverage of the deal, signed yesterday, Progressive Media has indicated it plans significant investment in the title.
Progressive Media is owned by Mike Danson, the founder of research company Datamonitor, who last week bought out MP Geoffrey Robinson's remaining half-share in left-wing political title The New Statesman.
Press Gazette had looked doomed after Wilmington revealed on April 6 it was ceasing publication of the title and was in consultation with staff. Wilmington had planned to keep the Press Gazette name and its website, which it emerged would no longer carry news but act as a community resource.
Dominic Ponsford, the editor of Press Gazette, said: "The purchase of Press Gazette is a positive sign for all journalists working on titles which, like us, are going through dramatic change at present.
"It proves the value that strong journalism brands have in an increasingly fragmented media world."
Press Gazette was first saved from closure in December 2006 when Wilmington bought the title out of administration.
The company behind it had been forced to fold when attempts to find new investors to take over from former Daily Mirror editor Piers Morgan and PR executive Matthew Freud failed.
Morgan and Freud bought Press Gazette and the British Press Awards from Quantum Business Media in 2005.