UPDATE 1-PREVIEW-Argentina data makeover gradual, at best

* New economy minister pledges statistics normalization

* Argentina wants to issue debt by end of year

* July inflation not seen changing trend (Adds Reuters poll figure)

By Guido Nejamkis

BUENOS AIRES, Aug 11 (Reuters) - Argentina has vowed to restore credibility in its economic data after claims it airbrushes indicators but analysts do not expect a sudden trend change in July inflation numbers due on Wednesday.

Economy Minister Amado Boudou, in his job for a month, has said Argentina will strengthen the National Statistics Institute, or INDEC as part of a push to return to international debt markets by late this year.

INDEC's inflation index is closely watched as a gauge of fixed-income returns and confidence in the data has collapsed over the past two years as economists alleged it significantly under estimated consumer price growth.

July's number is the first to come out since Boudou, who has not explicitly recognized problems with official data, took over at the economy ministry.

He is creating a council of independent Argentine academics to oversee statistics produced at the agency, widely accused of understating inflation since 2007 when then-President Nestor Kirchner put Domestic Commerce Secretary Guillermo Moreno at INDEC's helm.

Economists and financial analysts want more and say serious change cannot happen at the INDEC until Moreno is gone.

The government signaled Moreno may be there to stay when one of his allies was recently named to a new post as technical director at the agency.

"The government doesn't want to recognize its error so it has left the same man at the head of INDEC and assigns dozens of people to control him. It would have been easy to fire him," said independent economist Enrique Szewach.

DATA STILL LAGGING

Economists say the consumer price index probably rose some 1 percent in July, but the median expectation for the government figure was 0.6 percent in a Reuters poll of economists and financial analysts [nN11532886].

A Central Bank survey of economists forecast the government would report July inflation of 0.5 percent.

If the government reports July inflation of 0.7 percent or 0.8 percent that could indicate the numbers are being brought into line with reality, but most analysts said they did not expect that to happen.

Official numbers put the country's inflation at 7.2 percent last year, but private estimates are higher than 20 percent.

Argentina has been largely unable to issue bonds on international markets due to the threat of lawsuits from bond holders who did not enter its massive restructuring in 2005 after the biggest sovereign default in history in 2002.

The process of issuing new debt is also closely linked to market perceptions of whether the government correctly measures key economic indicators.

"It's indispensable for Argentina to return to the credit market, (but) any ratings agency that wants to review an Argentine bond is going to ask for the truest possible data about how the economy is working," said Jorge Todesca, former deputy economy minister who runs the Finsoport consulting firm.

Szewach said Boudou has sent mixed messages in his month as economy minister, trying to please financial markets and the so-called presidential couple, President Cristina Fernandez and her husband and predecessor ex-President Nestor Kirchner.

Argentine bond prices plunged last November to prices that implied default after Fernandez decreed a shock nationalization of private pension fund administrators.

Prices recovered in recent months as investor appetite for emerging market debt increased and the government made key debt payments. They do not have room to move much higher unless INDEC is cleaned up, said analyst Alejandro Vinitzky.

"It doesn't necessarily have to come fast, but a normalization of the statistics would help the rising trend in local bonds," said Vinitzky of the Maxinver consulting firm.

Boudou has tried to manage expectations, saying last week recovering confidence in the INDEC would take time.

"There hasn't been time yet even to debate or discuss potential changes," he told a local television station. (Editing by Theodore d'Afflisio)