By Jennifer Cummings   Of DOW JONES NEWSWIRES  NEW YORK (Dow Jones)--Anadarko Petroleum Corp. (APC) is particularly vulnerable to the fallout from the Gulf of Mexico oil spill, and its stock has reflected uncertainty related to liabilities and regulations that will result from the disaster.  Anadarko is getting hit on two fronts, observers said. First, because the company is BP PLC's (BP) partner in the leaking well, holding a 25%non-operating stake, it will likely be facing significant liabilities tied tithe cleanup and potential litigation.  Meanwhile, Anadarko is also hurt by the fact that it focuses on exploration in the Gulf of Mexico, a market that has stalled due to a six-month drilling moratorium. If and when the ban lifts, increased regulations are expected to push up the cost of doing business for companies in the Gulf, leaving Anadarko vulnerable.  A lack of clarity on how significantly Anadarko will be affected by those factors has made many analysts cautious on the company for the time being. But others called the selloff overdone, saying the market is overlooking Anadarko's other lucrative assets, including projects off the coasts of West Africa and Brazil, both hot areas for offshore exploration.  A representative from Anadarko couldn't immediately comment for this story.  The offshore drilling group took a massive hit Tuesday on concerns about the drilling ban and after BP's initially promising effort to plug the leak failed over the weekend. Anadarko was one of the weakest performers Tuesday, falling nearly 15%, compared with a 4.3% drop in the energy group of the S&P 500.  The group was getting some relief Wednesday on gains in the price of crude oil futures and the broader markets. However, caution remains strong--in the market for credit-default swaps, the cost of insuring BP and other deep-water drilling companies' debt rose.  Shares of Anadarko were recently up 4% at $43.84, but the stock is still down about 41% since the explosion of the Deepwater Horizon rig caused the spill on April 20.  UBS said in a note