* IMF deals restored Romania's credibility with investors
* Leu falls to one-week low
* Romania performs poorly without IMF supervision: analyst (Adds quote, details, background)
By Luiza Ilie
BUCHAREST, Feb 9 (Reuters) - Romania failed to reach an agreement with its international creditors on its aid deal as Bucharest resisted calls for gas price hikes and restructuring state-run coal firms, Prime Minister Victor Ponta said on Monday.
A series of aid agreements with the International Monetary Fund (IMF) and the European Commission has supported Romania since 2009, nudged the eastern European country to make its economy more competitive and keep its fiscal deficit in check. The latest deal, a 4 billion euro standby agreement, expires in September.
The deals have restored Romania's credibility with investors after a painful recession, and some like the high-profile investment fund Fondul Proprietatea have called on Romania to consider a new IMF agreement. The leu currency fell to a one-week low after Ponta's announcement.
During the latest round of talks, the IMF had called for Romania to hike gas prices for households and some industrial companies to 62 lei ($16) per megawatt from 53.3 lei by April, Ponta said.
As a result, the two sides failed to sign a letter of intent, without which Romania cannot draw on the IMF's funds in an emergency.
A new IMF mission will come to Bucharest in April for further discussions, Ponta said, adding that the IMF had called for "massive and radical restructuring" of Romania's state-run coal firms, without going into specifics.
"We are in agreement over taking measures to make them (the companies) more effective, Ponta said. But "we will not accept measures that will lead to the disappearance of the coal sector which is essential for the safety of our energy system and for the development of some regions."
Coal powers roughly 40 percent of Romania's power plants, but mines and plants are outdated and in dire need of investment. As part of the IMF deals, the government has merged mines and plants to create two integrated power holdings, with plans to privatise them.
Ponta in December said that Romania could seek a new type of arrangement with the IMF such as a flexible credit line, which would come with fewer conditions than the quarterly reviews the country has to pass to keep its standby deals going. Romania has no current plans to draw on the IMF funds.
"We expect this however to have short-term a limited impact on investor appetite for Romanian assets, given Romania's good macro indicators," BCR Research said in a note.
"Longer-term developments should be monitored closely given Romania's track record of poor economic decision-making during periods when the IMF was no longer in a supervising position." ($1 = 3.9300 lei) (Writing by Matthias Williams; additional reporting by Radu-Sorin Marinas)