UPDATE 1-Wolters Kluwer says on track to meet 2009 targets

* Keeps outlook for 2009

* Key revenue items grew slightly

* Says market conditions remain challenging

(Adds outlook detail)

AMSTERDAM, May 6 (Reuters) - Dutch publisher Wolters Kluwer NV (WLSNc.AS) said on Wednesday it kept its operating margin outlook of around 20 percent for 2009, despite tough trading conditions during the first quarter.

Wolters Kluwer Chief Executive Nancy McKinstry said in a statement that news subscription sales were weak in the first quarter but in line with expectations, and that cost-cutting had allowed the company to keep its margins in line.

Subscription revenue and revenue from non-cyclical sources, which make up 71 percent of total revenue, grew slightly in the first quarter from a year earlier, the company said in a trading update.

The company said in February it expected its earnings before interest, taxes and amortisation (EBITA), excluding exceptional restructuring expenses, margin to be broadly in line with 2008's 20.1 percent, despite continued weak economic conditions.

Ordinary diluted earnings per share is anticipated to be between 1.41 and 1.46 euros.

Wolters Kluwer publishes professional information in legal, tax, and scientific fields. Its main rivals are Reed Elsevier (REL.L)(ELSN.AS) and Thomson Reuters (TRIL.L)(TRI.TO). (Reporting by Reed Stevenson)