With just one trading day left in 2012, it's a good time to check how the stock prices of the area's biggest corporate giants fared.

Nine stocks of the Philly 50 companies, each of which employ at least 1,100 people in the Philadelphia region, are finishing 2012 lower: PNC Financial Services Group Inc. (down 0.36 percent), United Parcel Services Inc. (down 0.49 percent); Quest Diagnostics Inc. (down 0.59 percent), DuPont Co. (down 2.34 percent), GlaxoSmithKline P.L.C. (down 4.96 percent), Teva Pharmaceutical Industries Ltd. (down 7.83 percent), Public Service Energy Group Inc. (down 9.30 percent), Exelon Corp. (down 33.00 percent), and SuperValu Inc. (down 70.44 percent).

SuperValu, the parent company of Malvern-based Acme Markets Inc., has been the subject of possible takeover speculation since July. The Minnesota-based supermarket chain operator has struggled financially with long-term debt that stood at $6.1 billion as of Sept. 30.

The steep fall by Exelon, which owns the Peco electric and gas utility in the Philadelphia area, may seem unusual for a player in the staid electric utility business. But swoons happen when the CEO raises the possibility of a dividend cut, as Chris Crane did on Nov. 1.

Teva, an Israeli brand-name and generic drugmaker that has its U.S. headquarters in North Wales, Montgomery County, has yet to retrace its way higher after transitioning to a new CEO in May. The stock failed to rally after management talked with analysts earlier this month about a restructuring plan to better align the operations Teva has acquired over the years.

A tenth company also saw its shares fall 25 percent this year, but Caesars Entertainment Corp. didn't begin trading until its Feb. 7 initial public offering at $9 a share.

The biggest gainers in 2012 were US Airways Group Inc. (up 152.27 percent), PHH Corp. (up 110.09 percent), Bank of America Corp. (up 104.32 percent), Community Health Systems Inc. (up 73.02 percent), and eBay Inc. (up 64.23 percent).

While it has been clear skies for most airlines, with the 10-stock Bloomberg U.S. airlines index up 29 percent, US Airways has benefited from its pursuit of an acquisition of American Airlines, whose parent AMR Corp., is in bankruptcy court.

Operating as it does in the commercial fleet management services and mortgage businesses, Mount Laurel-based PHH isn't a household name like many of the companies on the list. But results continued to improve in PHH's profitable mortgage production unit.

Finally, Bank of America, which not only has branches in the region but also a major credit card operation in Wilmington, may be the nation's second-largest bank, but it flirted with penny stock status until it rallied in 2012 from $5.56 where it ended 2011.

Contact Mike Armstrong

at 215-854-2980 or marmstrong@phillynews.com, or @PhillyInc on Twitter.