None of the major parties reported to be the favorites to buy Simon & Schuster has commented on the pending acquisition—but that doesn’t mean sides aren’t being drawn.

During News Corp’s annual meeting yesterday, CEO Robert Thomson said he wouldn’t “speculate on speculation and scuttlebutt” that News Corp subsidiary HarperCollins was a leading contender to buy S&S. But he did offer a view on reports that Penguin Random House and its parent company, Bertelsmann, is a front-runner for S&S.

“I would make one observation about Simon & Schuster,” Thomson said in response to a question. “It will clearly be a serious antitrust issue if Bertelsmann acquires Simon & Schuster. However cute and clever the structure, if Bertelsmann is their beneficiary, it will be a book behemoth. And this will certainly be a profound antitrust issue for the entire book industry and, no doubt, for authors around the world.”

Bertelsmann CEO Thomas Rabe told The Financial Times in September that the company would likely make an offer for S&S when the time was right. He also told the paper that he didn’t think a S&S purchase would raise antitrust concerns. “We looked at this and we don’t think it is an issue,” Rabe told the FT. “If you look at the market holistically, particularly the strength of Amazon, and it includes self-publishing and the like, we don’t think this will be an obstacle.”

HC, with estimated U.S. sales of about $1.1 billion, is a distant second to PRH in the American book market. PRH’s U.S. sales are about $2.2 billion. A purchase of S&S, which has revenue of $814 million, would close the gap considerably.