The move came after the sights of swathes of empty seats at events in the first days of the Games prompted anger from people who had struggled to get tickets.
London 2012 chairman Sebastian Coe had promised to urge international federations to make sure they used areas reserved for them to avoid embarrassment.
Jackie Brock-Doyle, Locog's director of communications, said they had been able to get back 3,000 and re-sell them - a move they will do each day to make sure as many seats as possible are filled.
"We talked to the International Federations yesterday, we were able to put back into the pot for sale around 3,000 tickets last night, they have all been sold," she said.
"That includes about 600 for the gymnastics event today and we're going to do that on a day-to-day basis."
She said they were talking to accredited groups, including broadcast media and seeing if they can release some tickets.
"Where we can we are going to release those the night before and put them up for sale.
"Three thousand went up for sale last night and they have all been sold this morning."
London Mayor Boris Johnson said there had been discussion on "how to crack the ticketing problem" when ministers met in the Cabinet Office this morning.
He insisted he was pleased with the way the capital's transport network was operating during the Olympics so far.
He revealed that organisers had been able to turn off some of the dedicated Games lanes due to officials opting to travel by public transport.
Asked about the content of the meeting, he told Sky News: "Just what you'd expect - a lot of congratulations to all the organisers of the opening ceremony, thanks for everybody who ran the Torch Relay, which was the most the successful Torch Relay any country has ever put on. Talking a bit about how to crack the ticketing problem"
He added: "Obviously the transport, we're pleased with the way it's working so far, everybody at London Bridge was working well, the Tube is working well, the ORN.
"Actually, we've been able to turn off a lot of the Games lanes because so many people are going by public transport.
"It turns out a lot of the Olympic bureaucrat types who could go in the Games lanes, the T3 people as they're called, are using public transport.
"Jacques Rogge himself (president of the International Olympic Committee) today took the DLR, I'm proud to say, and was conveyed in stately style and comfort he'd expect on the DLR, and a lot of them are doing that and that is good news."
Mr Johnson added that he would be watching the diving this afternoon.
He said: "It's such a big day again. I'm going to see the diving this afternoon and everybody's got their fingers crossed."