(Adds Dutch finance ministry comment)
LONDON, March 16 (Reuters) - ING said on Thursday it was no longer a primary dealer for Slovenian government bonds, while the Dutch finance ministry said Nordea had become a dealer in its debt after several banks quit making markets in its treasury bills last year.
The number of primary dealers in European bond markets has been declining steadily as increased regulation since the 2008 financial crisis put pressure on banks' balance sheets.
Primary dealers buy government bonds directly from a country's debt management office and sell them on to investors in the market. They typically are also entrusted with maintaining secondary trading activity, which entails holding some of those bonds on their balance sheets for a period.
The Association for Financial Markets in Europe (AFME) said in a report on Wednesday that the average number of primary dealers in the European Union has fallen to around 18 from around 23 in 2006.
In an emailed statement to Reuters, a spokesman for ING, said: "As of 2017, ING is no longer a primary dealer for Slovenian government bonds."
ING's move follows a recent decision by Credit Agricole to exit bond dealer roles in Austria and Ireland, and in treasury bills for the Netherlands.
The Netherlands lost UBS, BBVA and DZ Bank as dealers exclusively in their bills in 2016 - so-called single markets specialists - a spokeswoman for the finance ministry confirmed in an emailed statement to Reuters.
She added that Nordea became a primary dealer in bonds at the start of 2017, replacing Santander, which has become the only remaining exclusive dealer in bills. While the number of primary dealers is unchanged at 15, the number of banks dealing bills fell from 20 to 16 over the last year. (Reporting by John Geddie; Writing by Dhara Ranasinghe; Editing by Larry King)