Investors weighing the potential of a fine of $10 billion or more for the French bank for allegedly breaking economic sanctions on Cuba, Iran and Sudan have more prosaic concerns: Will BNP be forced to raise more capital or suspend dividends, and will legal sanctions stop it earning its way out of a hole?

The answers may not be as bad as many fear. Investors might well breathe a sigh of relief at the certainty that comes with any final outcome.

So, political machinations aside, where would a $10 billion hit leave BNP? Core capital, backed out of its reported first-quarter fully loaded Basel III ratio, is €65.4 billion ($89.34 billion). At today's exchange rates and subtracting the €1.1 billion BNP has reserved, the hit from the fine would be €6.2 billion, excluding any tax adjustment. On risk-weighted assets forecast by Goldman Sachs analysts to be €630.5 billion at the end of 2014, BNP would be left with a capital ratio of 9.4%, beneath the 10% minimum it needs.

But the bank will make money this year. Analysts estimate €5.1 billion absent any litigation charges that could result from the U.S. action, according to FactSet. This gets the bank back to 10.2%.
That would be behind peers but not disastrous. However, to stay there BNP likely must scrap its dividend plans. Doing so would save €2 billion to €2.3 billion, although that would harm a stock that sports a dividend yield of 2.9%.

Putting payouts on hold also would bolster BNP's leverage ratio, a straight comparison of capital and total assets that regulators and investors like for its simplicity. Berenberg Bank analysts calculate the capital base for this ratio at about €72 billion, while consensus forecasts for total assets at the end of the year are €1.831 trillion.

With the same penalty and profit math, BNP's year-end leverage ratio would be 3.9%. That would be below many U.S. peers, but comfortably above a 3% minimum threshold. So BNP may be able to swallow a big fine without having to raise additional capital, a dilutive move.

But shareholders can't breathe too easy, for two reasons. First are Europe-wide "stress tests," due to be completed in August. Those could cause swings in BNP's risk-weighted assets and so its capital needs.

Second is the impact of any ban on transacting in the U.S. that could result from the charges. Goldman analysts take a sanguine view, saying the U.S. business is relatively small. They estimate the direct impact would be to cut 2016 earnings by 13%, leaving the bank trading cheap to the sector at 8.9 times 2016 earnings versus a 9.2 times average.

Yet that may underestimate the effect any ban could have on BNP's relationship with global corporate clients. If they take their business elsewhere, BNP will have a much tougher time earning its way back to real strength.