* Transneft says plant suspends oil product supplies
* Rosneft says expects Ryazan refinery back to normal by Feb. 19
(Adds Transneft comments, detail)
MOSCOW, Feb 13 (Reuters) - Russia's top oil producer Rosneft said it had halted output of oil products at its Ryazan refinery, a key fuel supplier to Moscow's airports, after a fire late on Wednesday caused by a railcar crash.
Oil pipeline monopoly Transneft said the 340,000-barrels-per-day plant, located 200 km (125 miles) southeast of Moscow, had suspended oil product supplies and crude oil intake, but had reserves to cover demand from the airports for a week.
Rosneft said several rail cars decoupled from a locomotive and then rolled backwards to crash through the gates at the plant, sparking a fire. It said no one was hurt in the incident at the refinery, one of Russia's largest.
"Due to safety reasons, the (plant's) units are switched to circulation mode, which is planned for an emergency," Rosneft said in a statement.
Rosneft said the fire had been extinguished by 5 a.m. local time (0100 GMT) on Thursday. A spokesman for the company said the refinery would resume normal work by Feb. 19.
Last year, the plant refined 17.3 million tonnes of oil, producing 4.1 million tonnes of diesel, 3.3 million tonnes of gasoline and 1.1 million tonnes of jet fuel.
Rosneft had planned to carry out maintenance at the plant, bought together with the Anglo-Russian TNK-BP oil firm last year, in April.
A spokesman for Transneft said the company planned to divert crude oil, originally destined for the Ryazan plant, to the Baltic Sea ports of Primorsk and Ust-Luga.
"If the plant resumes its work in a week, consumers will not feel any consequences from the Ryazan refinery stoppage," spokesman Igor Dyomin said.
He added that a key storage hub, Volodarsky, in the Moscow region, had 30,000 tonnes (over 220,000 barrels) of fuel reserves, while daily consumption stood at 4,000 tonnes.
(Reporting by Vladimir Soldatkin; Editing by Elizabeth Piper and Dale Hudson)