Revenues at golfer Rory McIlroy's management and image rights firm last year soared almost three fold to $17.64m (€16m). 

That is according to new accounts which show that the Dublin-based Rory McIlroy Management Services Ltd last year recorded a pre-tax loss of $6.29m. 

However, the pre-tax loss arises after a non-cash write down of $18m in the golfer's image rights during the year in accordance with accountancy rules. 

The accounts disclose that the cash generated by the company from operating activities after tax totalled $12.9m for 2018. 

The main activity of the company is managing royalty earnings and management fees for the golfer. 

Prize money and other such earnings are not part of the Irish company's revenue because they tend to be treated as income, and taxed accordingly by the country where the earnings are won. 

On the US PGA tour in 2018, McIlroy recorded tour earnings of $4.4m and already this year McIlroy has almost doubled his US PGA tour earnings to $7.78m. 

The earnings for the McIlroy company from royalties and management fees last year increased by $11.34m or 180% from $6.29m to $17.64m. 

The directors of the company state that "income levels were in line with expectations". 

The company recorded an operating loss of $4.3m and interest payments of $1.9m resulted in the pre-tax loss of $6.29m. 

It recorded a post tax loss of €7.4m after paying corporation tax of €1.146m. 

The company's cash pile increased from $829,219 to $2.14m. 

At the start of last year, the company had a $261m book value placed on McIlroy's image rights and it reduced that to $243m at the end of last year. 

Rory McIlroy's father, Gerry, sits on the board with MD Donal Casey and Sean O'Flaherty. 

Last year, the pay to directors almost doubled from $1.056m to $1.993m. Rory McIlroy joined the board in January of this year. 

At the end of last year, the firm employed six made up of three directors and three in administration. Staff costs last year increased from $1.78m to $2.77m. 

The company trading as Rory McIlroy Inc, was established towards the end of 2013 by McIlroy.

McIlroy works in many countries but opted to locate everything to do with his brand and intellectual property in Ireland by setting up the firm here as part of a strategy to simplify his business affairs. 

In setting up the firm in the Republic, McIlroy spurned the route often taken by superstar sports personalities by creating a complex structure that would have located his management company in the US while protecting his wealth with tax havens such as the Virgin Islands or Bermuda.