British travel firm Thomas Cook, facing heavy criticism over its handling of a family tragedy on the Greek island of Corfu, announced on Wednesday a reduction to first-half losses.

Losses after tax stood at £302 million ($469 million, 421 million euros) in the six months to the end of March compared with a net loss of £364 million during Thomas Cook's first half one year earlier, the company said in a statement.

Revenue slid nine percent to £2.742 billion over the period.

In the past week, people have gone on social media sites calling for a boycott of Thomas Cook after it emerged the firm received about £3.0 million compensation from a hotel chain responsible for the deaths of two British children killed by carbon monoxide poisoning in Corfu in 2006.

Thomas Cook has said it would donate £1.5 million to UN children's agency UNICEF, while the remaining money went to its insurers for underwriting legal fees.

Speaking to the Financial Times on Wednesday, Thomas Cook chief executive Peter Fankhauser said he is "deeply sorry" over the deaths and apologised for the company's handling of the incident.