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”).

Maxcom Telecomunicaciones SA de CV Sponsored ADR’s (MXT) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. Maxcom Telecomunicaciones offers local and long distance telephone services to residences and small to medium-sized businesses, as well as conference calling, data transmission, and high-speed Internet access. In Portfolio Grader’s specific subcategories of Earnings Growth, Equity and Cash Flow, MXT also gets an F. For more information, get Portfolio Grader’s complete analysis of MXT stock.

Cincinnati Bell (CBB) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). Cincinnati Bell is a full-service regional provider of data and voice communications services and equipment that operate over wireline and wireless networks. The stock gets F’s in Earnings Revisions, Cash Flow and Sales Growth. The stock price has dropped 10.7% over the past month, worse than the 1.7% decrease the S&P 500 has seen over the same period of time. For a full analysis of CBB stock, visit Portfolio Grader.

Portugal Telecom, SGPS S.A. Sponsored ADR (PT) experiences a ratings drop this week, going from last week’s D to an F. Portugal Telecom S.A. offers domestic, long distance, and international telephone, mobile telephone, paging, Internet access, and data communications services. The stock also rates an F in Earnings Surprise. To get an in-depth look at PT, get Portfolio Grader’s complete analysis of PT 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.