HARBIN, Oct. 12 (Xinhua) -- China has officially opened a sea route linking its landlocked northeastern province of Heilongjiang with its eastern coastal hub of Shanghai after it reached an agreement with Russia to use its port of Vladivostok.

The route through the Sea of Japan has been in trial operation since March and received final approval from China Customs.

The first shipment - 261 tons of paper - has reached Shanghai after starting from China's border city of Suifenhe in Heilongjiang and being transported via Vladivostok.

The shipment cost was ten percent less than it would have cost to transport it by land, said Zhang Yonglin, an official with the Suifenhe Port Commission.

China is also involved in discussions with Russia and Japan to establish a cargo route between Heilongjiang and Japan's port of Niigata, which would halve the distance and shipment time.

China's plan to revitalize its northeast industrial base bordering Russia and the Korean Peninsula has helped create a speedy transportation channel to the Sea of Japan. Inland provinces, including Heilongjiang, Jilin and Inner Mongolia Autonomous Region, are expected to benefit from the new sea outlet.