Yonkers, N.Y. ? Nearly a third of cell phone customers surveyed are seriously considering switching companies because of poor service, but there’s no easy way to figure out which plans are best, Consumer Reports magazine said.

“Deciphering one plan is hard enough, but comparing plans from various carriers is nearly impossible,” said Jim Guest, president of Yonkers, N.Y.-based Consumers Union, which publishes the magazine.

In addition, he said during a news conference Monday, companies made it difficult to switch by refusing to let customers keep their phones or phone numbers when they move to another company — and by charging early termination penalties of up to $175.

A Federal Communications Commission regulation that would let customers keep their phone numbers when they switch is scheduled to go into effect in November. Sprint PCS spokesman Dan Wilinsky said his firm was ready to meet that deadline.

But Chris Murray, Consumers Union’s telecommunications policy analyst, said the companies had twice persuaded the FCC to postpone it and were trying to do so again.

Guest said cell phone companies consistently were unclear about startup fees, roaming charges, early termination penalties and even when night and weekends begin and what “nationwide” means, all of which can drastically affect a customer’s bill.

Howard Waterman, a Verizon Wireless spokesman, said every new customer is sent a detailed explanation of the calling plan, with all terms defined carefully.

But Guest described the current state of the industry as a “cell hell” for consumers.

“The cell phone industry has made great strides in offering consumers sleek cell phones with the latest gee-whiz gadgets and gizmos, color screens, games, individualized rings and Internet access,” he said. “But the cell phone industry is not providing the nuts and bolts — the basic services consumers depend on.”

Sprint's system does not require cell phones to have any extra attachments for Internet service. Sprint has contracted with several Internet sites to provide text-only pages that fit the small screen. According to a new survey, Sprint's service is ranked near the bottom by consumers.

Even the ability to make a 911 call is affected, he said. The magazine found that emergency cell phone calls often failed because they were limited to one company’s signal, even if a rival’s signal was stronger in the area.

Waterman took issue with that claim, saying, “We treat 911 calls with the utmost priority. … Our policy is ‘find a signal, period,’ even if it’s a competitor’s signal.”

The magazine said a survey of 21,944 subscribers found numerous complaints of dead zones, busy signals and dropped calls. It compared service in six cities — New York, Washington, Chicago, Dallas, Los Angeles and San Francisco — and found that Verizon Wireless led the ratings in each.

Wilinsky, of Sprint, which finished last in four of the cities, said the results are “old news,” especially for Sprint.

Consumer Reports suggested that customers do homework before signing on with any carrier.

Consumers Union is a nonprofit organization that works to protect consumers through product testing and public information efforts.