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”).

Level 3 Communications‘s (NYSE:LVLT) rating falls this week to an F (“strong sell”), down from last week’s D (“sell”) last week. Level 3 is an integrated communications network company that provides Internet Protocol and data services, content distribution services, colocation services, and softswitch and voice services. In Portfolio Grader’s specific subcategories of Equity and Cash Flow, LVLT also gets F’s. The stock price has fallen 12.6% over the past month, worse than the 1.8% increase the S&P 500 has seen over the same period of time. For a full analysis of LVLT stock, visit Portfolio Grader.

This week, Nippon Telegraph & Telephone (NYSE:NTT) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Nippon Telegraph & Telephone provides a variety of telecommunication services, including telephone, telegraph, leased circuits, data communication, terminal equipment sales, and related services. The stock gets F’s in Earnings Surprise and Sales Growth. To get an in-depth look at NTT, get Portfolio Grader’s complete analysis of NTT stock.

This week, France Telecom‘s (NYSE:FTE) rating worsens to an F from the company’s D rating a week ago.France Telecom provides telecommunications services to residential, professional, and large business customers. The stock also rates an F in Sales Growth. For a full analysis of FTE 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.