The Dublin-based fashion designer, Louise Kennedy, whose customers include Kylie, Beyoncé and Meryl Streep, saw accumulated profits at her design firm Signum almost double in 2011 to €313,116.

A spokesman for the firm yesterday attributed the increase in business last year to significant growth in the export market.

The company spokesman said: "We can confirm 2011 produced satisfactory results largely arising from a significant growth in the export market."

A spokesman said the company was currently recruiting additional staff for Ireland and the United Kingdom.

"The company continues to make significant investment in product design," he said.

Ms Kennedy established her eponymous label in 1983.