Units of Brookfield Infrastructure Partners (BIP 0.78%) have tumbled nearly 24% this year and recently hit a 52-week low at less than $31 a unit. That's a much steeper slide than shares of its corporate twin, Brookfield Infrastructure Corporation (BIPC 0.42%), which have only declined by about 10% this year.

Because of that, right now looks like an incredible opportunity to buy units of the high-yielding partnership. They're trading at a widening discount to the corporate shares:

BIP Chart

BIP data by YCharts.

A fantastic bargain

Brookfield Infrastructure Partners and Brookfield Infrastructure Corporation are two sides of the same coin. Investors in either entity have the same economic interest in a globally diversified portfolio of infrastructure businesses.

The only difference is that one gets taxed as a limited partnership (and sends investors a Schedule K-1 for tax purposes), and the other is a regular corporation (that sends investors a Form 1099-Div for tax purposes). Those Schedule K-1s can make tax filing more challenging, which causes many investors to prefer the corporate shares since they can own them in a tax-deferred account like an IRA.

However, investors are paying a hefty premium for the simpler tax forms. Shares of Brookfield Infrastructure Corporation currently trade at more than $40 per share, while partnership units sell for under $31 per unit. That's an eye-popping 30%+ difference in price for the same underlying business that's on track to produce $2.70 per share/unit of funds from operations (FFO) this year.  

Because of that disconnect, investors buying the corporate shares are paying 14.9 times FFO. While that's a reasonable price to pay for such an excellent business, those who purchase units of the partnership are only paying 11.4 times for those same earnings, which is a downright bargain for this business. Another advantage of buying the partnership units is that they offer a higher yield of nearly 4.7%, compared to a 3.6% dividend yield on corporate shares.

An even more incredible bargain when factoring in the growth

Brookfield Infrastructure is having an excellent year. The company is benefiting from high inflation rates because 70%-75% of its earnings come from sources with annual rate-escalation clauses tied to inflation. In addition, it has been actively rotating assets by selling mature businesses and redeploying the proceeds into higher-returning opportunities.

These drivers have Brookfield Infrastructure on track to grow its FFO per share by 12% to 15% next year or to more than $3 per unit/share in 2023. Because of that, the corporate shares trade at less than 13.5 times its 2023 FFO estimate, while partnership units sell for only about 10 times that same FFO estimate. While that makes both cheap, the partnership units are an even more unbelievable bargain.

Meanwhile, Brookfield Infrastructure anticipates that elated inflation levels, upcoming capital project completions, and other internal growth drivers will power organic growth at or above its 6% to 9% per-share/unit annual target range over the next few years.

It can enhance that growth through further asset rotation. To pay roughly 10 times cash flow for a business growing at a double-digit rate is an extraordinary opportunity.

This earnings growth should enable Brookfield Infrastructure to deliver on its plan to increase the shareholder payout by 5% to 9% per year. The company has an excellent track record of growing its payout, delivering its 13th straight year of increases in 2022. The future growth will further enhance the partnership units' income yield for investors who buy that entity. 

A better way to invest in this top-notch dividend stock

There's a widening gap between the price of Brookfield Infrastructure's corporate shares and partnership units. Because of that, investors can lock in a much higher income yield and even more upside potential with the latter. That makes the partnership units look like an incredible investment opportunity right now.