Boston Properties suffers downgrades

KeyBanc downgraded Boston Properties to “underweight’’ and set a $90 price target for the stock. Despite a “fortress balance sheet and high quality office portfolio,’’ the stock price appears excessive and earnings growth not as impressive as it might be, KeyBanc’s analysts said. In addition, RBC Capital cut the stock to “sector perform’’ from “outperform,’’ and Barclays Capital cut its price target to $108, with an “overweight’’ rating.