BAKU, Dec 2 (Reuters) - Azerbaijan's state oil fund said it had invested $475 million to help fund construction of the new Star oil refinery in the west of Turkey. The fund said on Monday it would provide another $300 million next year for the $5 billion refinery project, which aims to start production in mid-2017 with an annual crude processing capacity of 10 million tonnes. Azeri state energy company SOCAR is building the Star refinery in partnership with Turcas Petrol TRCAS.IS to supply Turkish petrochemical company Petkim PETKM.IS and reduce Turkey's dependence on imported refined products. The $34 billion Azeri state oil fund invests the revenue from its oil contracts, oil and gas sales, transit fees and other revenues and uses the proceeds to help finance social spending and infrastructure projects. SOCAR said earlier this year it would also borrow about $3 billion on the international markets to finance the project. SOCAR signed a $3.46 billion engineering procurement and construction contract with a consortium comprising Tecnicas Reunidas TRE.MC , Saipem SPMI.MI , GS Engineering & Construction 006360.KS and Itochu Corp in May 8001.T . (Reporting by Nailia Bagirova; Writing by Margarita Antidze; Editing by Jane Baird) ((margarita.antidze@thomsonreuters.com)(+995322999370)(Reuters Messaging: margarita.antidze.thomsonreuters.com@reuters.net)) Keywords: AZERBAIJAN FUND/REFINERY