In early 2004, convenience-store chain Sheetz announced plans to sell beer at one of its 195 Pennsylvania locations.

But about three years passed before a single customer was allowed to purchase brew at the store in Altoona, Blair County.

And since February, beer sales have twice been halted and then resumed as Sheetz has found itself embroiled in a legal fight that has reached the state Supreme Court.

While the battle directly impacts only a fraction of Pennsylvania's beer drinkers, it serves as a prime example of the complexity of the state's alcohol regulations -- a system in which any proposed change is sure to ignite a firestorm of controversy.

"The case points out a system in Pennsylvania that is much different from almost any other state in the union," said Mike Cortez, Sheetz vice president and general counsel.

While there are many varieties of beer-sales licenses in Pennsylvania, consumers mainly buy from three types of establishments. Each has its own set of rules set by the state:

n Beer distributors sell by the case but cannot currently offer beer in smaller quantities such as a six-pack.

n Businesses with "restaurant liquor licenses" -- for instance, a bar or restaurant -- can sell beer, wine and liquor. But only beer may be offered as a carry-out purchase, and these licensees can sell nothing larger than a 12-pack.

Requirements for these establishments include serving food to the public in a space that measures at least 400 square feet and has accommodations for at least 30 people.

n Businesses with "eating place malt beverage" licenses are allowed to sell only beer; consumers cannot purchase more than two six-packs or a 12-pack at a time.

These facilities also must sell food and have room for at least 30 people, though the total space requirement is decreased to 300 square feet.

Because of this strict setup, the beer-license system has fostered a host of interest groups that, as a matter of financial survival, must zealously guard their respective share of the market.

So it is no surprise that a bill that recently passed a state Senate committee is generating plenty of feedback.

The proposal would allow beer distributors to sell packages as small as a six-pack. Also, other licensees would be able to offer up to three six-packs -- or previously unavailable 18-packs -- to a single carry-out customer.

While that sounds like a relatively small shift, the bill is opposed by trade associations representing nearly all sectors of the beer industry.