Independent telecommunications firms are seeking to block -- or at the least place severe restrictions -- on the proposed mergers of phone goliaths SBC-AT&T and MCI-Verizon Communications, claiming they could be wiped out by the absence of competition.

Firms such as Reston,Va.-based XO Communications that provide phone and Internet services to businesses using the phone giants' networks said they and their customers will be stuck paying much higher prices if the mergers go through unabated.

SBC in January proposed buying AT&T for $16 billion, while Verizon a month later launched a $6.7 billion offer for MCI that ultimately rose to $8.5 billion in May in the face of better offers from competitor Qwest Communications.

Public utility commissions in several states, including Pennsylvania, Ohio, California, New York, New Jersey and Virginia, must approve the two mergers, as well as the Federal Communications Commission and antitrust regulators at the U.S. Department of Justice.

XO and other independent firms say they currently can choose among at least two wholesale suppliers in every market, with MCI and AT&T bidding against the former Baby Bells Verizon and SBC to keep prices down. But once AT&T and MCI are formally gobbled up by SBC and Verizon, respectively, the independents fear their options will be next to nil as the two giants opt to let each other have markets to themselves.

The mergers will give SBC and Verizon control of more than 95 percent of the market in most areas, said Douglas Kinkoph, XO's vice president of regulatory and external affairs. The end result, he said, will be higher prices that will most likely be passed onto customers.

Merger supporters, including the companies, deny that there won't be competition and say new technology such as wireless and Internet phone service continues to give customers new ways to use phones. But Kinkoph and other opponents say much of the new technology is too small and too far away from broad implementation to be of use to businesses now.

Pennsylvania's PUC has just begun considering the mergers, accepting testimony on behalf of the companies after opponents were given their shot earlier this summer.

Hearings on the SBC/AT&T merger will be held in mid-August, with the Verizon/MCI hearings following in mid-September.

XO, which had sales of $1.3 billion last year, said it is battling the buyouts not because it fears going out of business but because the merged firms will have an unfair competitive advantage or "monopoly" on offering communications services to consumers.

"The big impacts will be on the smaller [telecom] companies," said XO spokesman Alan Gilbert.

Even so, other other independent telecom providers that are smaller have chosen to remain mum on the issue.

Officials at the San Jose, Calif.-based telecom firm Covad Communications, which has revenue of $429.2 million, declined to comment on the mergers, referring instead to a press release from early May in which San Antonio-based SBC said it, alongside AT&T, would continue its current business relationship.

Yet Covad, which has customers in the Pittsburgh area, is a part of a loose alliance of smaller telecom providers that are fighting the mergers at the federal level, expressing their opposition with the FCC and the Justice Department.

The coalition, known as the Alliance for Competition in Telecommunications, has hired high-profile Silicon Valley-based lawyer Gary Reback.

State consumer advocate Sonny Popwsky said he was less concerned about what he labeled as the "troubling" mergers' effect on competitors than he was on residential consumers. With fewer competitors in the marketplace, he said, consumers inevitably will confront higher costs for phone, Internet and eventually pay-TV service.

"These companies will become even more dominant and harder to compete against," he said. "If there's not a lot of competition, then you really need to have stronger regulation."

Not everyone agrees.

Scott Cleland, an analyst at the Washington, D.C.-based telecom research group Prescursor, said in testimony before a Senate subcommittee in April that the alternative phone services -- including wireless and Voice-over-Internet-Protocol, or VoIP -- are creating options for businesses and consumers. Solid regulation, he added, will ensure that the marketplace remains competitive.

University of Pittsburgh business professor Ravi Madhavan agreed, noting that large mergers don't always shut out their smaller competitors. "As a general rule, it leaves opportunities on the periphery," he said, meaning the smaller companies will most likely not be crowded out but instead have the chance to go after more specialized customers.

In the meantime, XO is one of several detractors that have submitted written testimony to the state PUC rebuking the mergers. The process will probably continue through the fall.

"We want to make sure that the PUCs know that people are watching them and that people at least have their eyes wide open," said Gilbert.