Venezuela on Tuesday announced agreements worth more than $500 million with three Chinese companies to boost iron production and transport in the latest strengthening of bilateral ties.

The first contract will see Hong Kong-based Wisco International Resources Development provide machinery and spare parts for railroads at a cost of $200 million, the state news agency AVN reported.

The other two agreements, with the China Communications Construction Company (CCCC), for $161 million each, will improve iron transport infrastructure in and around the eastern river port of Palua and dredge the Orinoco River.

Venezuela's President Hugo Chavez has moved to strengthen ties with China in recent years as a counterweight to the United States, which he frequently denounces as an "imperial" power.

China has invested heavily in Venezuela's oil, gas and mining sectors in recent years and has sold Caracas 18 Chinese K-8 fighter jets.

The two countries have also agreed to build a $140 million observation satellite in Asia and launch it from South America in 2012.