NEW YORK (TheStreet) -- No doubt about it: Professional sports have the potential to score big growth for investors. According to a PwC report released last fall, North American pro sports will rake in $70.7 billion in revenue in 2018, up 24% from 2013.

But with most teams privately owned, investors have few ways to elbow into this lucrative industry. To date, only four teams -- soccer's Manchester United (MANU) - Get Report , the National Hockey League's Florida Panthers, the NBA's Boston Celtics and baseball's Cleveland Indians -- have traded in the U.S. as independent entities, and the best spin you could put on the results is "mixed."

The Indians, whose flirtation with the market lasted only a year, saw their shares slump as low as $6 from their IPO price of $15 before eventually rising to $20.63 after the team's sale was announced in November 1999. (Shareholders eventually received $22.61 a share when the club was taken private.)

Meanwhile, the Celtics, which traded from 1986 to 2002 as a master limited partnership, saw their units drop from the IPO price of $18.50 to $11.35 until new ownership bought a majority interest in the MLP and then purchased the remainder.

Clearly, sports stocks have no free pass when it comes to the risks of investing. In fact, those risks are multiplied when decisions are clouded by emotions like a "passion" for a given team or sport. Instead, you should consider using an unemotional, rules-based investing approach like the one described in a free report called The 29 Most Dangerous Stocks

Nonetheless, if you're game to grab onto a small piece of the sports business, here are three stocks worth considering.

  • Manchester United. This English football -- er, soccer -- club listed shares on the New York Exchange in 2012. This was actually its second offering following a listing on the London Stock Exchange in the 1990s, a period during which Man U's stock performed a lot like that of the Celtics. The latest iteration has seen healthier performance, with the stock rising 25% since the IPO date, but that's still well behind the S&P 500's 35% gain during that time.The club, 80%-owned by the Glazer family of the U.S. (which also owns the NFL's Tampa Bay Buccaneers), ranked No. 5 on Forbes' 2015 list of the 50 most valuable global sports franchises.The team is forecasting record profits in its 2016 fiscal year, which ends June 30, 2016, thanks to its return to playing in the UEFA Champions League after missing out in the 2014-2015 season. Last year Man U signed a deal under which Adidas  (ADDYY) will pay 750 million pounds over 10 years to make the Red Devils' shirts. But, according to The Telegraph, Adidas's annual payments will fall 30% if the team fails to make the Champions League for two consecutive seasons, starting with the 2015-2016 season.Man U also recently announced its first dividend since its 2012 IPO: $0.045 a share to be paid Oct. 15 to investors of record on Sept. 30. That gives the stock a 1% yield, based on today's price.
  • The Madison Square Garden Co. (MSG) - Get Report Apart from Manchester United, the only way to invest in sports teams in North America is through conglomerates.The Madison Square Garden Co. is a good example. In addition to the venue from which it takes its name, the company owns the NBA's New York Knicks, the NHL's New York Rangers and the New York Liberty of the Women's National Basketball Association. The company also owns the Hartford Wolf Pack and Westchester Knicks, development squads for the Rangers and New York Knicks, respectively.In addition to its sports ventures, MSG creates and produces live events, owns theatres and operates TV networks.MSG is splitting into two new companies: the Madison Square Garden Co., which will take the existing MSG ticker and will hold the company's sports teams, theaters and other venues; and MSG Networks Inc., which will take the ticker MSGN and will own the company's media properties.The split, which has just been completed, could benefit both companies. A 2012 study by Credit Suisse looked at spinoffs over the previous 17 years and found that, on average, spun-off firms outperformed the S&P 500 by 13.4% in the first 12 months, while their parent companies topped it by 9.6%.
  • BCE  (BCE) - Get Report owns 37.5% of Maple Leaf Sports and Entertainment, which, in turn, owns the Toronto Maple Leafs of the NHL, the NBA's Toronto Raptors, Toronto FC of Major League Soccer and the Toronto Marlies, the Leafs' development team. BCE also holds a stake in the Toronto Argonauts of the Canadian Football League and 18% of the Montreal Canadiens NHL team.The NHL still trails Major League Baseball, the NBA and the NFL in popularity in the U.S., but these two teams are quality assets. The Leafs, for example, were the only NHL club to make the Forbes list this year, clocking in at No. 37, with a value of $1.3 billion.BCE's sports holdings barely scratch the surface of its operations. For example, one of every four Canadians subscribes to its wireless service, and the company also runs some of the country's most popular TV channels, including the TSN sports network and CTV television, along with 106 radio stations.Investing Daily has dubbed BCE the "best yield play in Canada" because of its 60-year track record of sustaining and growing its dividend. The shares currently yield 4.8%, and over the past decade, BCE's payout grew at an average rate of 9% annually.

Even though publicly traded pro sports investments are a rarity, these three aren't the only game in town. Other options include Rogers Communications (RCI) - Get Report , another Canadian telco that competes with BCE and holds 37.5% of Maple Leaf Sports and Entertainment as well as 100% of the Blue Jays, and World Wrestling Entertainment (WWE) - Get Report , which, if you were a kid in the '80s, you may remember as the World Wrestling Federation.

Besides Man U there are other publicly traded soccer teams but they are listed on foreign stock exchanges. Those teams include the Juventus Football Club SpA, AS Roma SpA and SS Lazio SpA, all of which trade on the Italian Stock Exchange, and the Frankfurt-listed Borussia Dortmund.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.