DOHA, Oct 23 (Reuters) - Petrochemicals, metals and fertiliser producer Industries Qatar IQCD.QA (IQ) posted a 28.9 percent drop in third-quarter net profit on Sunday, according to a statement.

The Middle East's second-biggest petrochemicals company by market value reported a net profit of 759.7 million riyals in the three months ending Sept. 30, Reuters calculated, based on financial statements in lieu of a quarterly breakdown.

This compares with the 1.41 billion riyals it posted in the corresponding period of last year, while the average forecast of three analysts polled by Reuters was for a quarterly net profit of 996.6 million riyals. urn:newsml:reuters.com:*:nL8N1CQ0H6

IQ's results are closely tied to oil prices and global economic growth because its products are used extensively in construction, agriculture, industry and manufacturing.

Industries Qatar had reported falling profits in eleven of the previous 13 quarters.

The firm's net profit for the first nine months of 2016 was 2.73 billion riyals, down on the 3.83 billion riyals it made in the same nine months of last year, it said in a statement.

(Reporting by Tom Finn; editing by Andrew Roche) ((Tom.Finn@thomsonreuters.com;))