The country's foreign trade deficit for the nine months widened by 76.1% year-on-year to 2.079 billion euros, according to non-final data based on customs declarations and Intrastat reports.
Excluding mineral products, the country's exports fell by 4.6%, while imports rose by 1.9%.
Exports of Lithuanian-origin goods alone dropped by 2.7%; excluding mineral products, these exports rose by 1.7%.
Lithuania's key export partners in the nine months were Russia with 13.3% of the total exports, Latvia with 10.2%, Poland with 9.7% and Germany with 8.1%.
Russia also topped the import rankings with 17.5% of all imports, followed by Germany with 11.6%, Poland with 10.2% and Latvia with 7.3%.
The key export markets for Lithuanian-origin goods were Germany with 11.1%, Latvia with 8.2%, the United States with 7%, and the United Kingdom and Poland with 6.9% each.
Russia remains an important foreign trade partner for Lithuania, but exports of goods of Lithuanian origin to that country slumped down by 54.2% in the nine months through September compared with a year ago, figures from Statistics Lithuania showed.
The decline was mainly due to a 94.3% drop in milk and dairy product exports and an 86.5% fall in exports of electrical machinery and equipment and parts. Moreover, Lithuania exported no meat and meat sub-products to Russia this year, the statistics office said.
Exports of Lithuanian-origin food and farm products to Russia this year plunged to a mere 46 million euros, from 195.8 million euros in the same period last year.
Lithuania's total exports to Russia, including re-exports, shrank by an annual 41.4%, with food and farm product exports, including re-exports, alone down by 59%.
Russia accounted for 13.3% of Lithuania's total exports (including re-exports) in January through September, but Lithuanian-origin goods made up just 9.7% of the total value of its exports to that country.