LVIV, Ukraine (Reuters) - Traders have exported the first supplies of Ukrainian corn to Europe by train as the country's sea ports remain blocked due to the Russian invasion, APK-Inform agriculture consultancy said on Sunday.

       Ukraine is a global major grain grower and exporter and almost all its exports have traditionally been shipped from its Black Sea ports. Monthly grain exports exceeded 5 million tonnes before the war.

       Traders and agriculture official have said Ukraine, which still has significant volumes of grain in stock, may start exporting by train via its western border.

       "The first batches of several thousand tonnes of corn have already been exported across Ukraine's western land border," APK-Inform said in a report.

       "Difficulties with logistics persist, supply still prevails over demand, but prices have stopped falling," it added.

       APK-Inform said Ukrainian corn DAP (Delivered At Place) prices for buyers from Poland and the Baltic States were $250 to $265 per tonne and $275 per tonne for Slovakia.

       Ukrainian transport authorities have said as much as 600,000 tonnes of grain per month could be exported by trains from Ukraine to Europe.

       APK-Inform said last week Ukraine's grain exports could total 44 million tonnes in the 2021/22 July-June season. It expected only 1 million tonnes of grain to leave the country from March to June due to logistics problems.

       (Reporting by Pavel Polityuk; Editing by Lincoln Feast.)