UPDATE 1-Two French hostages leave Algerian gas site -minister
* French minister says no news on two other hostages
* Cannot say if hostage crisis over, information patchy
* Catering worker hid for 40 hours away from kidnappers
* 150 Algerian catering employees safe, company says
PARIS, Jan 18 (Reuters) - French authorities are in contact with two French hostages who have left the desert gas facility in Algeria where they were being held by Islamist militants, France's Interior Minister Manuel Valls said on Friday.
Thirty hostages and at least 11 of their captors were killed on Thursday when Algerian forces stormed the desert gas plant in a bid to free many dozens of captives, an Algerian security source said.
Valls told RTL radio that information from the In Amenas site was patchy and he could not say if the operation was over. A diplomat in London said Britain had not received any information to suggest the hostage situation had ended.
One French hostage, an employee of a French catering company, said he had remained hidden for nearly 40 hours in a room separately from other foreign hostages. He survived thanks to supplies brought to him by Algerian colleagues.
"When the military came to get me, I did not know whether it was over," said Alexandre Berceaux. "They arrived with colleagues (Algerians who worked with him), otherwise I would never have opened the door."
Berceaux said Algerian military forces were still combing the sprawling gas site for hidden hostages when he was escorted to a nearby military base, from where he expected to be transferred shortly to France.
"They are still counting them up," he told Europe 1 radio.
Regis Arnoux, chief executive of the CIS Catering company, which employs some 150 Algerians at the In Amenas plant, told Europe 1 that all of his employees were safe. They had been held separately from Western hostages.
"I had exchanges during the night with the head of my subsidiary in Algeria who told me the 150 Algerians were safe and sound," he said.
Valls said authorities had no information about two other presumed French hostages. "As for the two others, if there were two others, we ... hope to get new information early today."
Valls advised against criticising the North African state and hailed its efforts to end the stand-off, after British Prime Minister David Cameron said he had not been sufficiently informed about Algerian plans for a raid.