Vonage shares dip sharply

Shares of Internet telephony pioneer Vonage Holdings dropped sharply in their trading debut, dismaying customers who had been given a chance to participate in the IPO, an Associated Press report said.

The report said the firm's shares closed at $14.85 on the New York Stock Exchange, down 12.6% from the offer price of $17 per share.

It was the worst first-day drop for an IPO so far this year, the report said.

The drop was surprising, considering pre-IPO demand had appeared healthy. The 31.25 million shares were sold in the middle of the expected range of $16-$18 each, the report said.

The stock opened close to its IPO price, then quickly dipped, which panicked some investors, analysts said, according to the report.

Vonage's 1.6 million subscribers plug their phones into adapters that connect to their broadband Internet connections. Under one of its plans, it charges $25 a month for unlimited calling to the US, Canada and parts of Europe.