Vonage loss narrows but customer growth slows

(Adds CEO interview, revenue, and share move)

By Ritsuko Ando

NEW YORK, May 8 (Reuters) - Internet-based phone company Vonage Holdings Corp (VG.N) on Thursday reported a narrower first-quarter loss after cutting marketing spending, but customer growth slowed drastically as a result.

Vonage said its net loss shrank to $9 million, or 6 cents a share, from a loss of $72 million, or 47 cents a share, in the same quarter a year earlier.

Revenue for the first quarter rose 15 percent to $225 million. Analysts on average expected revenue of $224.5 million, according to Reuters Estimates.

The results helped Vonage shares rise 8 percent in pre-market trade, but details showed that the improvement in finances had come at a cost.

Vonage added only 30,000 net subscriber lines in the quarter, a sharp decline from 56,000 additions in the previous quarter and 166,000 in the year-ago quarter.

"We spent less money, and obviously that's going to translate into slower growth. That was a conscious decision by the company," Chairman Jeffrey Citron told Reuters in an interview.