LONDON (Reuters) - Experian Plc (>> Experian plc), the world's biggest credit data company, forecast an end to adverse foreign exchange movements that have hit its revenue as it reported an unchanged full-year pretax profit.

The FTSE-100 company, which is best known for running consumer credit checks for banks, landlords and retailers, said on Wednesday that profit before tax was $1 billion (692 million pounds) for the year-ended 2015, the same as a year earlier.

The company had warned in January that if current rates prevail, it expected a hit on earnings before interest and tax from exchange rate movements of about 11 percent for the year ending March 31, and a further hit of about 3 percent next year.

"If recent rates prevail, we no longer expect foreign exchange to be a headwind for the year ending 31 March 2017," Chief Executive Brian Cassin said in its earnings report.

Experian's revenue fell 4 percent from the previous year to $4.5 billion, in line with analysts' estimates according to Thomson Reuters I/B/E/S.

Experian, along with two other major credit reporting agencies, Equifax Inc (>> Equifax Inc.) and TransUnion , generate credit reports and scores based on consumers' borrowing and payment habits, including bankruptcies and court judgements.

Experian reported costs of $20 million arising from the data breach last October that exposed sensitive personal data of some 15 million people who applied for service with T-Mobile US Inc .

Experian said it discovered the theft of the T-Mobile customer data from one of its servers on Sept. 15. The computer stored information about some 15 million people who had applied for service with telecoms carrier T-Mobile during the prior two years, Experian said.

Connecticut's attorney general said he would launch an investigation into the breach and Massachusetts Attorney General said she expects a multi-state probe would be launched into the breach.

(Reporting by Noor Zainab Hussain in Bengaluru and Lawrence White in London, editing by Louise Heavens)

Stocks treated in this article : Equifax Inc., Experian plc