Israel's Teva Pharmaceutical, the world's largest generic drugmaker, reported on Wednesday a 16-percent drop in revenue and a net loss of 2.94 billion U.S. dollars in the fourth quarter of 2018.

Following the report, Teva shares dived 9.99 percent in Wednesday's premarket trading in New York, and by 7.69 percent on Israel's Tel Aviv Stock Exchange, after it went down nearly 12 percent during the trading on both exchanges.

Teva's revenue for the quarter shrank to 4.6 billion dollars, compared with 5.5 billion dollars from a year ago.

Its annual revenue also declined by 16 percent, from 22.4 billion dollars in 2017 to 18.9 billion dollars in 2018.

The main reason for the decline is a sharp drop in sales of Copaxone, Teva's flagship drug for multiple sclerosis, due to competition.

Teva expects revenue at around 17 billion dollars in 2019, 4.5 percent lower than the average estimate of analysts.

Teva's CEO Kare Schultz said in a conference call with company's investors that it would shut down 11 factories in 2019 to reduce debts.