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”).

Premiere Global Services, Inc.’s (PGI) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. 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 currently has a trailing PE Ratio of 36.90. To get an in-depth look at PGI, get Portfolio Grader’s complete analysis of PGI stock.

inContact, Inc. (SAAS) earns a D this week, moving down from last week’s grade of C. 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. For more information, get Portfolio Grader’s complete analysis of SAAS stock.

KT Corporation Sponsored ADR (KT) ratings are on the decline this week as the company earns an F (“strong sell”). Last week, it received a 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 a full analysis of KT stock, visit Portfolio Grader.

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.