Owners of the Pittsburgh Post-Gazette said they have found a buyer who had agreed to keep the newspaper open, less than a month before it was due to shut down. Block Communications said that the Venetoulis Institute for Local Journalism, publisher of the digital-only Baltimore Banner, had agreed to buy the Post-Gazette. The newspaper dates its history to 1786, and if it had been closed, it would have left Pittsburgh as the nation’s largest community without a city-based newspaper. Terms of the deal were not closed. The Post-Gazette said it would continue to publish print editions on Thursday and Sunday.