Updated at 7.00pm: MTR Corp's decision to offer fare concessions over a six-month period has added bad news to its profitability and stock prices, according to analysts. The offer, which awards passengers with one bonus ride for every 10 rides, is estimated to lose about HK$450 million in revenue, or about one-tenth of the urban subway service provider's HK$4.05 billion. Brokerages such as CLSA Emerging Markets and Indosuez W.I. Carr Securities recommended a sell on the stock on higher risks in comparison to other blue chip utilties. An MTRC spokesperson said yesterday the corporate had yet to ascertain what the financial impact would be arising from the fare concession. ''We will constantly review the response during the six months,'' she said. The corporation cited relieving the public's pain from economic downturn as the aim of the offer. Starting from December 10, passengers is entitled to a free trip after taking 10 rides on any MTR trains within one week. They have to redeem the free trip in MTR customer service centres. ''That's a key factor in deciding how much the corporation is going to lose in revenue. I don't think everyone will take the inconvenience to redeem the freebie,'' an analyst of a Europe brokerage said.