KHOBAR, Saudi Arabia, Nov 1 (Reuters) - Saudi Arabia's Sadara Basic Services, fully owned by Sadara Chemical Co, has signed agreements covering storage facilities and port services, it said on Sunday as the firm prepares to start producing petrochemicals by the end of this year.

Sadara Chemical is a $20 billion petrochemical joint venture between national oil giant Saudi Aramco and U.S. firm Dow Chemical. The partners have said the venture will go ahead on schedule despite slumping global oil and petrochemical prices.

Sadara will sell some tank storage facilities to Jubail Chemical and Storage Services Co (JCSSC) at cost for around 1.76 billion riyals ($470 million), it said in a Saudi bourse statement.

Meanwhile, JCSSC will provide bulk storage and product handling services to Sadara for 20 years at the King Fahd Industrial Port in Jubail. JCSSC, owned by Saudi Basic Industries Corp and Vopak, has a storage and shipping terminal at the port.

(Reporting by Reem Shamseddine; Editing by Andrew Torchia and Adrian Croft)