Christine A. Varney heads up antitrust at the Department of Justice, and she's going hunting. She is the point person for a group consisting of the presidential administration and some Congressional Democrats that is looking to put the breaks on large companies in several industries.

Already, airlines have run into roadblocks when requesting relief from antitrust regulations. Varney & Co. are digging into complaints by AT&T (NYSE: ATT) and Verizon (NYSE: VZ) that cable competitors – e.g., Cablevision (NYSE: CVC) – have locked them out of the market for cable company-produced programming.

(Imagine that, a phone company complaining! Usually, they're the objects of derision.)

The short interest in Sirius (NASDAQ: SIRI) spiked up between November 15 and November 30 by 14.4 million to 113.4 million.

Sirius shares have been down over the last few days, and perhaps the market thinks they will go lower.

Many analysts expected that the Sirius merger with XM Satellite Radio (NASDAQ: XMSR) would be approved by now. No such luck. The longer the approval drags on, the better the chance that it will get derailed by ranting congressmen of the Justice Department.

Then, there is the issue of the Sirius balance sheet. The company has long-term debt of about $1.3 billion and no way to repay it. With bad credit markets, it may not even be able to be refinanced. The company had an operating loss of $106 million last quarter on $242 million in revenue. And subscriber counts are not doubling year-over-year like they used to.

Sirius is in trouble. The market knows it. And it needs that merger and the savings it should bring to stay afloat.

Douglas A. McIntyre is an editor at 247wallst.com.

Microsoft (NASDAQ: MSFT), finally seeing the writing on the wall after losing in the European courts, decided today to withdraw its appeal [subscription required] of an antitrust ruling by the South Korea Fair Trade Commission, according to a report in the Wall Street Journal today. "It is important to note that Microsoft remains committed to Korea and continues to work closely with the FTC to ensure that Korean consumers benefit from vibrant competition in the IT industry," the company said in a statement. I bet that's how they really feel. I don't think Microsoft truly wants to help the competition, but they are being forced to do so by the antitrust regulators.

In February 2006, South Korea's FTC imposed a fine of 32.5 Korean ($35.4 million) against Microsoft for abuses related to its dominance in certain software, primarily its Windows operating system. Microsoft must provide two versions of Windows in Korea, one stripped of the Windows Media Player and Windows Messenger and the other carrying links to Web pages that allow consumers to download competing versions of such software. Microsoft appealed this decision in March 2006. This appeal was turned down in May 2006 by the FTC and it asked the antitrust regulator to review the fine. Today Microsoft dropped the appeal most likely because it realized it would lose.