UPDATE 1-Mauritanian leader appoints party chief as premier

(Adds entire government resigns, paragraph 3, background)

By Vincent Fertey

NOUAKCHOTT, May 6 (Reuters) -Mauritania's president replaced his prime minister on Tuesday with a loyalist who heads his new political party, the official news agency reported.

A reshuffle had been widely expected in the sparsely populated Saharan state which has faced unrest over rising food prices in recent months as well as a spate of al Qaeda attacks.

President Sidi Mohamed Ould Cheikh Abdallahi accepted the resignation of Zein Ould Zeidane and his government, the Mauritanian Information Agency said.

Zeidane, a former central bank chief, came in third place in a presidential election last year in which he stood against Abdallahi. He backed Abdallahi in a run-off vote and was rewarded with the post of prime minister when he won.

In his place Abdallahi has appointed Yahya Ahmed El Waghef, who had been general secretary at the ministry in the presidency and heads the National Pact for Development and Democracy (PNDD-ADIL), which Abdallahi created after coming to power.

No official reason was given for Zeidane's replacement and there was no indication when Waghef would name his new cabinet.

The administration has been criticised over its response to a string of attacks by al Qaeda's north African arm, including the Dec. 24 murder of four French tourists and the subsequent cancellation of the annual Dakar motor rally on security grounds.