The LED lights maker's shares were down about 20% on the warning.

The company has faced numerous challenges this year including high costs related to a former manufacturing partnership that went sour. The chief executive officer and chairman were also replaced.

Dialight now expects its 2019 earnings before interest and taxes (EBIT) to be between 5 million pounds ($6.48 million) and 8 million pounds, after adjusting for some costs.

The company reported EBIT of 8 million pounds last year and in July said it expected to report underlying operating profit of 10 million-13 million pounds.

Dialight said on Tuesday the market for its division that supplies traffic lights remained weak and does not expect it to recover until the second half of 2020.

"With our exposure to U.S. markets, the uncertainty of the trading relationship with China continues to be a significant headwind as we enter our traditionally busiest period," the company said in a statement.

North America, which accounted for 73% of Dialight's sales in 2018, has also been challenging for the firm due to issues after it moved production of its designs to U.S.-listed Sanmina Corp.

On Tuesday, Dialight said it has been unable to reach a settlement with Sanmina so far and was exploring all options to recover costs related to the issue and exit the partnership.

(Reporting by Pushkala Aripaka in Bengaluru; Editing by Shailesh Kuber)