International building materials group CRH once again occupies the number one position in the The Irish Times Top 1000 survey, the guide to Ireland's leading businesses.

CRH leads the field thanks to the €18.6 billion turnover it earned last year. Multi-national, Microsoft, retains the number two slot it held in the 2012 list with a turnover of €13.7 billion and Google comes third with sales of €12.5 billion.

While there is a strong multi-national presence amongst the lists's leaders, Irish businesses, including Kerry Group, Musgrave, Paddy Power and Ryanair all feature in the top 20.

Companies are ranked according to turnover, but the 56-magazine and website, top1000.ie, produced in association with KPMG, also highlight a number of trends in business.

This includes a focus on the top performers, those businesse that have grown revenues and profits over the last year, this year's leader is technolog group, Zynga.

With an eye on the future, the publication, edited by Irish Times journalist Fiona Reddan, also highlights those that are likely to break into the list in coming years. Healthcare group Kelpac Medical, pricing data specialist Profitero and social media giant Twitter, which opened its international HQ in the Republic two years ago, all feature amongst this group.

Another addition to the survey is a focus on advisers, which analyses the popularity of both banks and law firms amongst the leading Irish corporates.

Following on from its Auditwatch survey last November, The Irish Times Top 1000 once again examines patterns in audit fees.

The magazine is available free with today's edition of the paper. The website, top1000.ie which is regularly updated, is subscription-based.

However, using the promotional code mag1000 readers can log in free today for a 24-hour period to get a taste of the service.