Shares of Growth Portfolio holding Weatherford International (NYSE: WFT) have tumbled more than 12 percent today, largely because the company has yet to resolve the tax accounting issues that management first disclosed a year ago. Last year’s revisions were all noncash restatements, and we expect the latest adjustments will also be noncash. This news has overshadowed the oil-field service outfit’s solid fourth-quarter results and encouraging operational trends.

Although this lingering accounting issue is frustrating, Weatherford International and its peers should continue to benefit from recovering margins in international markets and an upsurge in offshore exploration and development. A slew of recent discoveries in the Kwanza Basin off the coast of Angola and other deepwater fields have led to a faster-than-expected recovery in this market segment. At the same time, deepwater activity in the Gulf of Mexico also continues to pick up.

With profit margins likely to remain relatively flat in North American shale plays, investors should favor Schlumberger (NYSE: SLB) and Weatherford International, both of which have more exposure to international growth stories than Baker Hughes (NYSE: BHI) and Halliburton (NYSE: HAL).

Weatherford International has less exposure to natural gas-focused services in North America than any of its peers and has strong leverage to international markets and oil-related services. For these reasons, the stock has rallied more than 55 percent from its October low to last Friday’s close. That’s compared to the 36 percent gain posted by shares of Schlumberger, the 27 percent return posted by Halliburton and the 13.3 percent gain posted Baker Hughes. Even after today’s correction, Weatherford International’s stock will likely have outperformed shares of the other major services firms since that October low.

The investment case for Weatherford International continues to rest on its leading market position in rapidly growing markets such as artificial lift, a service line that enhances production from mature oil fields. I will analyze the company’s results and subsequent conference call in this week’s issue of The Energy Strategist.

Although the company’s failure to resolve this accounting charge is disappointing, today’s announcement is unlikely to undercut the case for investing in Weatherford International.

The company expects restatements of $225 million to $250 million related to 2010 fiscal year and prior–for comparison, the company’s gross profits on a trailing 12-month basis are more than $2.6 billion on more than $12 billion in revenue. Although additional inconsistencies could emerge and these numbers are hardly pocket change, these restatements won’t threaten the franchise.

The selloff in shares of Weatherford International appears overdone and is unlikely to stick. However, this latest misstep won’t help investors’ confidence in senior management; a shake-up could be in order at the top. Investors would likely cheer any leadership changes. At the same time, the company’s favorable positioning in the current operating environment and cheap valuation could make it a takeover target. Weatherford International rates a buy under 20.