NEW YORK (CNN/Money) - WorldCom, the nation's second largest long-distance provider, is making a marathon effort to retain its customers following its bankruptcy filing Sunday night.

Virtually everyone, from federal regulators to consumer advocates, insists that service will not suffer as the parent company of MCI restructures its business under Chapter 11 protection.

But some long-distance customers aren't waiting around to find out. WorldCom competitors AT&T and Sprint both cited an increase in customer inquiries by Web and phone over the past few weeks.

"We've seen an increase in the number of people inquiring about and switching over to our long-distance service," said Angie Makkyla, a spokesperson for Sprint. "There's a great deal of uncertainty in the market, and customers are taking this opportunity to re-evaluate their long-distance providers."

Some say competitors may try to capitalize on WorldCom's woes.

"I believe some companies are trying to get their hands on MCI's customers list, though I don't know if that will happen," Bill Hardekopf, a spokesperson for SaveOnPhone.com. "But providers would love to get their paws on it."

WorldCom's stock has plummeted since the company disclosed $3.8 billion in misstated operating expenses over a month ago. The company issued a statement Monday morning that operations will continue normally while it gets its financial house in order and reduces its debt load. Chapter 11 bankruptcy allows a company to reorganize free from the demands of creditors.

Most agree that bankruptcy does not necessarily mean a drop in service quality or pose a threat that service suddenly could be cut off. A spokesperson for the Federal Communications Commission (FCC), the government regulatory agency, said other providers that filed Chapter 11 in the past continued to provide services while restructuring operations.

"We do not believe this bankruptcy filing will lead to an immediate disruption of service to consumers or threaten the operation of WorldCom's Internet backbone facilities. WorldCom has obtained funding necessary to continue operations during its bankruptcy proceeding," said Michael K. Powell, FCC chairman.

Experts warn against jumping the gun. First, it's almost impossible you'll pick up the phone and find yourself without a dial tone. To cut off telecom services, the law requires that a provider file a petition with the FCC and notify its customers at least 31 days in advance of any service cutoff.

Residential and small business customers should stick with their WorldCom Internet access or long-distance plan if they consider it a good deal, advised Sam Simon, chairman of the Telecommunications Research and Action Center (TRAC), a Washington, D.C.-based group that acts on behalf of residential telecom customers.

"It's a good time to double-check and make sure you're on the right plan," Simon said. "You may want to keep a couple of 10-10 numbers or a pre-paid calling card in your back pocket, just for comfort, but you should be fine." Click here to do some comparison shopping.

But if long-distance or Internet service is critical to your business operations, you may want to consider developing a backup plan, Simon added.

"There is no reason to believe they would shut down, but simple prudence in business dictates that it's always good to have a plan B," he said.

For more advice from TRAC to WorldCom customers, click here.