East Japan Railway Co. said Tuesday it lost 2.1 billion yen in revenue in the nine days following the powerful earthquakes that struck Niigata Prefecture on Oct. 23.

JR East was forced to suspend Joetsu Shinkansen Line bullet train operations and other services in the area. It declined to reveal the overall cost of restoring services in the area, saying it still does not know the full extent of the damage.

It said it will accelerate reinforcement of piers supporting elevated railway tracks for the shinkansen networks it operates, following the first-ever derailment of a bullet train during 40 years of operations.

JR East said it plans to finish the work on 7,500 piers by around September. It had said earlier that it would complete the work by the end of March 2009.

Work on 2,900 more piers that still need reinforcement will have to wait for negotiations with tenants who have shops and other businesses underneath the elevated tracks.

JR East's Toki No. 325 on the Joetsu Shinkansen Line bound for Niigata from Tokyo derailed while running at about 200 kph near JR Nagaoka Station when the deadly quakes hit the area on the evening of Oct. 23. None of the roughly 150 passengers on the train was injured.

JR East lines have 82,000 piers supporting its elevated shinkansen tracks.Some 18,500 of these are deemed in need of reinforcement.

JR East said it has finished reinforcement work on 8,100 piers.

It said it normally costs about 1 million yen to reinforce each pier with a steel plate and concrete.