QUITO, May 5 (Reuters) – Ecuador is negotiating a $500 million loan with a state-owned oil company in Thailand to finance its 2015 investment plan, the finance minister said on Tuesday, coming at a time when government revenue has plunged due to lower oil prices. The finance minister, Fausto Herrera, declined to give further details or identify the oil company, but he was hopeful that Ecuador, OPEC’s smallest producer and which is highly dependent on income from exports of crude, would secure the cash by the middle of this month. Ecuador secured $7.53 billion of credit lines with China’s government in January, as it scrambles to patch up gaps in its financing after halving the $79.70 per-barrel estimate it originally expected would be the average oil price for this year. The Andean country of 16 million people has also taken out loans with Chinese oil companies in the last few years to be repaid with crude oil, and last year it obtained a $1 billion credit line from Noble Americas Corp. The socialist government’s debt levels are comparatively low at 29 percent of gross domestic product, and it expects to raise this to 35 percent. Ecuador typically produces around 550,000 barrels of crude a day. (Reporting by Alexandra Valencia; Writing by Peter Murphy; Editing by Leslie Adler) (([email protected]; +57 1 634 4133; Reuters Messaging: [email protected])) Keywords: ECUADOR THAILAND/LOAN