Mr Leterme had offered his resignation to the king twice before
Belgium's King Albert has accepted the resignation of Prime Minister Yves Leterme's government after the collapse of the ruling coalition, officials say.
A statement from the palace said Deputy Prime Minister Didier Reynders had asked to be relieved of his mission to mediate in the political crisis.
Mr Leterme offered his resignation last week after a liberal Flemish party quit the government.
It was the third time he had offered his resignation since July 2008.
The palace statement said that the king had asked Mr Leterme to stay on in a caretaker capacity.
After receiving Mr Leterme's resignation last Thursday, the king did not immediately accept it but instead asked Mr Reynders - a French speaker - to mediate. When Mr Reynders asked on Monday to be relieved of his mission, the government's resignation was accepted.
Mr Leterme said in a statement: "I regret that the necessary dialogue to achieve a negotiated settlement did not produce the result we hoped for."
Analysts say elections could take place in June - just before Belgium is due to begin its six-month presidency of the EU.
The five-month-old coalition collapsed after the Open VLD party withdrew over a long-running dispute on the special voting rights of French speakers living in Dutch-speaking areas near the capital Brussels.
Differences between the Dutch-speaking Flemish majority and French-speaking Walloon minority often threaten Belgian governments, but analysts have described the current crisis as particularly acute.