Shares in Tate & Lyle tumbled by almost a third this morning (28 September) after the UK company warned its sugar business would post a loss during the first half of the year.

Tate & Lyle blamed a "particularly difficult" August for the profit warning, which sent shares falling from 557.5p at the close of trade last night to 401.25p at 13:06 BST today.

The company said its sugars division is now expected to see a "small loss" for the six months to 30 September against a profit of GBP15m in the comparable period last year.

Furthermore, Tate & Lyle said the first half of the year had been flat for its Splenda sucralose and its US and European ingredients businesses. The company added that the weakness of the US dollar is expected to reduce pre-tax profits for the first half by GBP12m.

The company's European refining businesses had performed in line with expectations and were "making good progress in improving efficiency and competitiveness", Tate & Lyle said.

Tate & Lyle will publish its interim results on 31 October.