NEW YORK (TheStreet) -- Normally a full-year earnings disclosure is all about the numbers, but the new statement from the world's largest mining company BHP Billiton (BHP) - Get BHP Group Ltd Sponsored ADR Report   is different. The key message the company is giving is that it is too large and diversified now to be managed optimally -- and that change has to come.

And this is a big change.

For the last few months -- especially in the healthcare and technology sectors -- one of the most compelling themes in the global stocks markets has been a sharp uplift in merger and acquisition activity. BHP Billiton's announcement is the polar opposite of this. In essence, by unbundling the company's aluminium, coal, manganese, nickel and silver divisions, the company is reversing the merger of BHP and Billiton that occurred in 2001.

It is breakup time.

The global mining giants have been getting bigger and taking more market share over the last 15 years. The rationale for this has been simple: voracious demand from China created the opportunity, and bigger profits were available from striking larger and larger supply deals.

TheStreet's Ruben Ramirez speaks with The Deal's Paul Whitfield about the details of the breakup:

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The trouble is this theme has got muddied over the last five years or so. China may be continuing to grow, but the rest of the world has struggled. As for the mining companies they got bloated too -- buoyed by easy profits and convinced by the logic that bigger everywhere was clearly better.

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Bigger everywhere is not clearly better.

BHP Billiton is a top-three global company in iron ore, copper and coal production, plus it has extensive petroleum interests. These four areas generate over 90% of its profit. Simply put, the company is focusing on its strengths.

Focus. Stock markets generally like focus because it generally leads to a more profitable, efficient business. This gives options with the resulting cashflows generated, too.

To me, the lack of a share buyback announcement in the numbers from BHP Billiton (which did disappoint the market) can be chalked up to a lack of focus. The announcement of the breakup starts to address this problem.

I think the future looks bright for the core, continuing BHP Billiton business. As for the assets being spun off into a still-unnamed new company, more details really have to come out to make a call here. I do note that this business will be primary-listed in Australia, with a secondary listing in South Africa. That may cause some challenges for existing shareholders outside these countries.

Today BHP Billiton shares are down 3.86% to $69.96 as of 12:30 p.m., as the company's formal earnings numbers were a touch behind hopes and no buyback was announced. Unless the global economy disappoints again, sustained weakness from here would be wrong.

BHP may stand for "Break-up Has Potential."

At the time of publication, the author was long BHP.

This article is commentary by an independent contributor, separate from TheStreet's regular news coverage.