** Shares of Roomba vacuum cleaner maker iRobot IRBT.O slip 83% to 75 cents premarket after co files for bankruptcy

** Co filed for Chapter 11 protection in Delaware bankruptcy court on Sunday after raising concerns about staying in business in March

** Profits have been eroded by competition from lower-priced Chinese rivals and new U.S. tariffs

** According to the bankruptcy plan, co will be taken private by its primary manufacturer Picea, which will also cancel two loans IRBT owes

** Amazon.com AMZN.O had once attempted to buy IRBT in a $1.4 billion deal, but the plan was abandoned last year due to regulatory roadblocks

** Up to last close, IRBT is down 44.3% YTD

(Reporting by Avinash P in Bengaluru)

((Avinash.P@thomsonreuters.com))