Shares of PetroChina (NYSE:PTR), China's answer to the venerable ExxonMobil (NYSE:XOM), have sputtered recently. They're down some 14% since hitting an all-time high of $94.50 on Aug. 2, even as the AMEX Oil Index has skipped up nearly 11% over the same period. Is this pullback a sticky mess -- or a golden opportunity?

The key issues driving this retreat were an implosion of first-half refining margins -- from a sweet $7.20 per barrel in last year's period to $1.50 per barrel for the six months ended June 30 -- and a recent secondary offering of $2.7 billion.

Heck, I fully admit that I'm a perpetual optimist, but this reaction seems extreme.

First off, while the $734 million loss reported in refining operations isn't something to cheer about, it pales in comparison to the $10.4 billion operating profit recorded in PetroChina's core exploration and production business (a 61% gain for the period) and was almost offset by a near tripling of profits in the company's petrochemical division (to $711 million).

Did I mention that the Chinese government has raised its price cap three times this year, and that PetroChina itself said that it expects the refining business to improve in the second half of the year?

As for that $2.7 billion secondary offering, there's an attendant rumor that it prompted investment guru Warren Buffett's Berkshire Hathaway (NYSE:BRKa) to sell some of its 1.34% stake in the company. Personally, I'd love to have $2.7 billion worth of shares in my pocket, but it represents less than 2% of PetroChina's $142 billion-plus market cap. Furthermore, Berkshire Hathaway was not among the sellers, according to the term sheet.

In my humble opinion, this recent retreat was a tempest in a teapot. I'm not complaining, though -- it allows investors a cheaper entry point into what I believe is the world's most attractively valued major oil company.

Consider this: PetroChina currently trades at a mere eight times 2006 earnings estimates, a 27% discount to the average multiple of 11 afforded ExxonMobil, Motley Fool Income Investor pick Total SA (NYSE:TOT), and BP (NYSE:BP).

Sure, there's a China discount, but historically it's been around 10%. That discount itself is questionable in light of PetroChina's superior dividend yield -- 4.7% vs. BP's 3%, Total's 2.9%, and your grandparents' ExxonMobil with a mere 1.8%.

Furthermore -- and it's hardly a quantifiable issue, but I will Foolishly bring it up -- PetroChina's status as a Chinese company is a positive in the current race to secure energy supplies. Unlike Western majors, PetroChina is able to secure deals with nations that Washington frowns upon, such as Iran and Sudan, while China's perceived ability to act as a counterweight to the U.S. is attractive to governments in Russia and Venezuela.

So, what's not to like? With a cheap valuation, a fat dividend and excellent geopolitical and economic positioning for the future, PetroChina seems like a sweet investment to me.

In short, the recent pullback in PetroChina's shares is an opportunity for existing investors to top off their positions, while new investors get the chance to add a high-performance stock to their portfolios.

New Fool contributor WillFrankenhoff welcomes any NICE feedback. At the time of publication, he held no financial position in any companies mentioned above.