Slovenia will try to roll over debt maturing in June early with an auction of around 500 million euros worth of 18-month treasury bills on April 17, the finance ministry said on Thursday.

The ministry said it would make an offer to buy back 855 million euros in bills coming due on June 6 at a 99.525 percent of the papers' face value.

Slovenia is facing intensifying pressure from markets following the messy bailout of Cyprus last month. It failed to sell all of a planned tranche of 100 million euros in bills this week, and markets have been watching for signs of how it would approach refinancing the debt maturing in June.

(Reporting by Marja Novak; Writing by Michael Winfrey)