Forth's newspapers include Wee County News, Allanwater News, the Strathallan News and Eastside News in Alloa, and the East Kilbride Mail, Eastwood Today and Avondale Mail.
Holleran told Journalism.co.uk he had heard that the company was in trouble some weeks back, but said that trying to find out more information was proving difficult.
"It's like there's a veil of secrecy," he said.
It hasn't been possible to reach staff at either Forth Newspapers or any of the individual titles today.
Holleran said he understood that a decline in advertising revenue was to blame, but said he expected some of the titles to go up for sale, meaning there was "potential there for saving one or two of the newspapers".
According to a report in the Scotsman, a liquidator has been appointed and a buyer may be preparing to acquire some of the titles.
Martin Little, editor of Wee County News, told The Scotsman it was a "very sad day for all involved".
"Putting aside the personal disappointment, my thoughts are with the thousands of people who looked forward to receiving each of our titles every week. Communities have been at the heart of everything we have done."
UPDATE: Holleran has issued a statement on behalf of the NUJ: "The liquidation of Forth Independent Newspapers is the biggest sign yet of the crisis facing the Scottish newspapers industry.
"The closure of titles such as the Wee County News should worry everyone in publishing and alert the government to the dangers facing a free and diverse press in this country and stir them into action.
"While recognising the difficulties of Ministers intervening between publishers and their banks the NUJ believe there is an immediate need for the government to set up an all-party and stakeholder meeting to explore the benefits of setting up a Press Commission on similar grounds to the Broadcast Commission."
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