This week, the ratings of three diversified telecommunication services stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, Premiere Global Services, Inc. (PGI) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Premiere Global Services is a global provider of conferencing and collaboration services. In Portfolio Grader’s specific subcategory of Earnings Momentum, PGI also gets an F. The stock has a trailing PE Ratio of 29.80. For a full analysis of PGI stock, visit Portfolio Grader.

Slipping from a C to a D rating, inContact, Inc. (SAAS) takes a hit this week. inContact provides cloud-based contact center software services and network connectivity in the United States. The stock gets F’s in Earnings Revisions and Equity. The stock price has dropped 16.8% over the past month, worse than the 1.3% decrease the Nasdaq has seen over the same period of time. As of April 16, 2014, 129734850% of outstanding inContact, Inc. shares were held short. To get an in-depth look at SAAS, get Portfolio Grader’s complete analysis of SAAS stock.

KT Corporation Sponsored ADR (KT) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). KT provides telecommunication services including local, long distance, and international calling, satellite communication, data transmission, and wireless telephone services in South Korea. The stock receives F’s in Earnings Growth, Earnings Momentum, Earnings Revisions and Margin Growth. For more information, get Portfolio Grader’s complete analysis of KT stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.