The U.S. Supreme Court will hear a challenge Wednesday from motor transport associations in three New England states to a 2003 Maine law that seeks tighter regulation of online sales of tobacco products.

Maine Attorney General G. Steven Rowe said the state is defending significant portions of the law, which was intended to keep minors from avoiding over-the-counter age verification by using the Internet or phone to order cigarettes.

Motor transport associations in Massachusetts, New Hampshire and Vermont challenged the law, claiming it is pre-empted by the Federal Aviation Administration Authorization Act of 1994. The three trade associations’ members include such companies as UPS, Federal Express and DHL freight carriers.

At issue is a section of Maine’s law requiring that persons to whom tobacco products are addressed be at least 18 years old and that they sign for the package. If the buyer is under 27, a government-issued identification must be shown at the time of delivery.

The law also requires retailers that ship tobacco products to clearly indicate on the package that it contains tobacco products. Carriers must check packages to determine whether they bear such markings.

In addition to preventing underage purchases of tobacco products, the law was designed to assist the state in collecting taxes that would otherwise be unpaid.

In May 2005, U.S. District Judge D. Brock Hornby ruled in favor of the trade associations, saying that federal law pre-empts the state law. Maine appealed to the 1st U.S. Circuit Court of Appeals, which affirmed Hornby’s ruling a year later.

Rowe asked the U.S. Supreme Court to review the case.

Rowe said after the District Court ruling that states have well-established powers to adopt laws to keep youth from smoking. Hornby ruled that while Congress has written into the law some exemptions, the Maine Tobacco Delivery law fits none of them.