The fund value of prize bonds rose by 4.9% to €588.8m, according to the Prize Bond Company's annual report today.

A total of 145,793 tax-free prizes were awarded last year, an increase of 12.2% on 2005, with the total value of prizes up 9.4% to €13.9m. Meanwhile, sales on the internet rose 90% to €11.6m, and now account for 9% of all prize bonds sales.

The company said that despite significantly increased competition in the savings market, 2006 saw sales totalling €133.3m. Repayments in 2006 were €104.3m.

'Over the five-year period 2001-2006, sales have increased by almost 80%, with sales levels now over €100m for four consecutive years', it said.

Michael O'Keeffe, chairman, said strong online sales demonstrated the continued relevance of prize bonds as a tax-free, risk-free investment for Irish people.

He also told RTE radio that the company was looking at changing its prize structure. The current top prize is €150,000.