Kennedy, who had been interested in taking sole control of the club, announced he was joining forces with former Rangers director Murray after Ticketus, who were part of the Blue Knights's original bid, withdrew its support earlier on Friday.
Rangers, champions a record 54 times, went into administration in February over unpaid tax bills and efforts to find a buyer have suffered delays because of uncertainty about the club's status on and off the pitch.
"This offer we consider to be substantial," Kennedy and Murray said in a statement.
"[The offer] is conditional on a CVA [Company Voluntary Agreement] being approved by the creditors and [owner] Mr [Craig] Whyte's shares being acquired."
Asked if teaming up with Kennedy gave the bid extra motivation, Murray said on Sky Sports News: "I think it does. I've been speaking to Brian for several months... and we are speaking from the same page.
"It adds real muscle to the whole thing.
"This is the best and final bid. Time has now run out. It is time to choose someone."
"Ticketus today confirms it has withdrawn from the Blue Knights consortium after it was unable to finalise satisfactory terms of agreement for its investors with the Blue Knights around restructuring its ticket purchase agreement," the company said.
"Consequently Ticketus is no longer able to play a role in the consortium's bid for Rangers Football Club PLC at this stage."
Murray believes the joint bid is the only offer that guarantees the club's future.
"It's important to do a comparison between the two bids," he said.
"I'm not interested in anything that sees the club die, my understanding of Bill Miller's bid is the club would not survive."
