UPDATE 4-Belgium agrees to give KBC guarantees for debt

* Belgium agrees guarantees to cover KBC debt

* Media report KBC set to make 2-4 bln euro CDO writedown

* KBC declines comment, its shares are suspended

* KBC due to report Q1 results on Thursday

(Updates with deal reached)

By Philip Blenkinsop

BRUSSELS, May 13 (Reuters) - Belgium agreed on Wednesday to give banking and insurance group KBC NV (KBC.BR: Quote, Profile, Research) guarantees to cover the risk of losses on its debt portfolio after reports it had been forced to make a heavy writedown.

Details of the guarantees for KBC's collateralised debt obligations (CDOs) would be announced at a news conference on Thursday morning, the government said in a brief statement.

Belgian business daily De Tijd said on its website that KBC would have to write down between 2 billion and 4 billion euros ($2.7-$5.5 billion) on it collateralised debt obligation (CDO) portfolio.