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

Cresud S.A.C.I.F. y A.’s (NASDAQ:CRESY) rating falls this week to an F (“strong sell”), down from last week’s D (“sell”). Cresud is an agricultural company that makes basic agricultural commodities. CRESY also rates an F in Portfolio Grader’s specific subcategory of Margin Growth. The stock currently has a trailing PE Ratio of 37.30. For a full analysis of CRESY stock, visit Portfolio Grader.

This week, Brookfield Office Properties (NYSE:BPO) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Brookfield Properties operates as a commercial real estate company that owns, develops, and manages premier commercial office properties in select cities in North America. The stock also rates an F in Margin Growth. For more information, get Portfolio Grader’s complete analysis of BPO stock.

This week, FirstService (NASDAQ:FSRV) drops from C to a D rating. FirstService operates globally in the real estate services sector. The stock gets F’s in Earnings Growth and Earnings Momentum. As of Jan. 25, 2013, 23.4% of outstanding FirstService shares were held short. To get an in-depth look at FSRV, get Portfolio Grader’s complete analysis of FSRV 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.