** Office space REITs JBG SMITH Properties JBGS.N and Cousins Properties CUZ.N down after BMO Capital Markets downgrades rating on stocks

** JBGS shares down ~4% at $16.06 after brokerage downgrades co to "underperform" from "market perform"

** Cites declining office occupancy after Amazon's HQ2 failed to be a giant tech magnet for National Landing; lowers PT to $15 from $18

** Also notes Elon Musk and Vivek Ramaswamy's "DOGE Plan to Reform Government" has an unknown and potentially meaningful impact on office and multifamily demand in JBGS's sole focus in DC metro area

** CUZ shares down ~2% at $30.68 after brokerage downgrades co to "market perform" from "outperform"

** Brokerages cites less conviction of CUZ's market fundamentals despite its strong performance YTD and among competition, raises PT by $1 to $32

** YTD, including session's moves, JBGS stock has fallen 5.5% while CUZ rose 26%

(Reporting by Neil J Kanatt in Bengaluru)

((Neil.JKanatt@thomsonreuters.com))