By Seda Sezer and Tuvan Gumrukcu

ISTANBUL/ANKARA (Reuters) - Turkish President Tayyip Erdogan suggested on Thursday that emergency rule could be extended beyond a year and rounded on rating agencies after Moody's cut Turkey to "junk" status, helping send the lira to its weakest in almost two months.

In a speech in Ankara, Erdogan said Turkey would benefit from a three-month extension to the three-month state of emergency declared after a failed July 15 coup, which the government says is needed to hunt down those responsible, but which critics say is being used to stifle dissent.

"It would be in Turkey's benefit to extend the state of emergency for three months," he told a group of provincial leaders at the presidential palace.

He then went on: "They say one year isn't right for Turkey. Let's wait and see, maybe 12 months won't be enough."

Speaking a day after the National Security Council recommended the extension of emergency rule, Erdogan said the measure would strengthen Ankara's fight against terrorism, adding he believed Turks would support it.

More than 100,000 people, including members of the police, civil service and military, have been sacked or suspended since the failed coup, in which a group of rogue soldiers commandeered tanks and jets in an attempt to seize power, killing at least 240 people. Around 40,000 people have been detained.

Rights groups, some Western governments and Turkey's main opposition party have criticized the extent of the crackdown.

The head of the opposition Republican People's Party (CHP), Kemal Kilicdaroglu, said this month that the state of emergency should be used only to bring the country back to normal and that innocent people were suffering in the purges.

But the head of the Nationalist Movement Party (MHP), Devlet Bahceli, said on Thursday he supported the extension.

The government blames followers of Muslim cleric Fethullah Gulen for the coup attempt and says the purges are necessary to root out members of his network, a stance the MHP supports.

Gulen, who has lived in self-imposed exile in the United States since 1999, has denied involvement in the attempted coup and condemned it.

"THEY LOVE ME TOO"

Moody's cut Turkey's sovereign debt to non-investment grade, or "junk", late on Friday, citing worries about the rule of law, as well as risks from a slowing economy.

Erdogan, who has frequently lambasted rating agencies in the past, joked sarcastically about his strained relations with them and said Moody's move was political.

"I love rating agencies and they love me too ... Put a few cents in their pockets and get the rating you want, this is how they work," he said, adding investors had shown strong demand for Turkish debt at an auction on Monday.

"They suddenly cut our rating. So what? ... Cut Turkey's rating as much as you want, this isn’t the reality in Turkey," he said, adding nobody took ratings agencies seriously any more.

His comments were more combative than those of some of his ministers. Deputy Prime Minister Mehmet Simsek said Turkey would make "intense efforts" to restore its rating.

The lira hit its weakest against the dollar since Aug. 5 not long after Erdogan spoke, in what analysts said was largely a reaction to the extension of emergency rule.

"Probably the comments about the need for 12-month emergency rule...weighed more than the latest love fest with the ratings agencies," said Nomura strategist and veteran Turkey watcher Timothy Ash.

Erdogan announced the three-month state of emergency on July 20, saying it would enable authorities to take swift action against those responsible for the putsch.

(Additional reporting by Ayla Jean Yackley; Writing by Humeyra Pamuk and David Dolan; Editing by Nick Tattersall)