The latest valuation of Facebook Inc. may be inaccurate, according to a Bloomberg poll of 1,000 investors, traders and analysts, and is raising concern that a bubble may be forming in the technology sector.

Bloomberg reported that 69 percent of investors said Facebook isn’t worth $50 billion, the value given to the popular social networking site following a $450 million investment in the company by Goldman Sachs Group Inc.

Facebook’s latest round of financing efforts, which this month raised $1.5 billion, has made investors uneasy about Internet companies in general.

The Bloomberg poll, which was conducted Jan. 21-24 by Des Moines-based Selzer & Co., found that more than 50 percent of respondents think that the valuation signaled the “beginning of a dangerous new bubble” in the market. Only 10 percent of respondents said the valuation is accurate. Four percent said Facebook is worth more.

“Those investing in Facebook, expecting it to be the next Google, might be in for some bad news along the way,” said John Lee, a portfolio manager with Morristown, N.J.-based PGB Trust & Investments.

Bloomberg, citing unidentified sources said to be familiar with the matter, reported that Facebook’s revenues reached $1.2 billion in the first three quarters of 2010. Citing Forbes magazine, Bloomberg said Mark Zuckerberg, Facebook’s founder and CEO, has a net worth of $6.9 billion.