Athens' failure to accept Germany's help on reducing bureaucracy and boosting private investment is disappointing, German Economy Minister Philipp Roesler was cited as saying by a newspaper on Thursday.

Germany pledged last October to advise Greece on cutting red tape and attracting investment to help its economy get back on its feet and have a fighting chance to cope with its debt.

The agreement was struck during Roesler's visit to Greece as head of a 70-strong delegation of German industry representatives seeking business in the country.

The aid has hardly been accepted, a lot has been in vain so far, it is very disillusioning, Roesler told the Saarbruecker Zeitung.

The newspaper quoted a ministry progress report on the deal, which read: The implementation clearly is not a priority on the Greek side.

Companies wanting to invest in Greece have met with hurdles such as a multitude of approval procedures and unclear responsibility, according to the ministry.

It is not failing due to a lack of will, the fundamental problem are the structures, Roesler told the paper.

Roesler said he was also disappointed that some German companies which had previously done business with Greece had still not been paid.

The Greek side said during my visit that it would soon resolve the old cases, he said. Unfortunately there has been hardly any progress on this.

Germany has a big stake in the debt-stricken Greek economy. Athens has been one of the biggest buyers of German armaments over the past decade and German companies manage some of Greece's largest firms, including Athens International Airport, managed by engineering firm Hochtief.

Greece's cash-strapped hospitals owe dozens of millions of euros in arrears to German drugmakers and health equipment providers, such as Bayer.

Roesler urged the Greek government to do what was necessary to ensure it could return to growth.

Athens needed to create the necessary conditions for growth, by modernizing the administration, opening up its markets and implementing its privatization programme, he said.

Only when these steps have been seriously implemented will the willingness to invest increase, he said.

Greece, unable to borrow normally on the bond markets, urgently needs a bailout agreed last month to keep paying its bills while it attempts to make deep structural reforms to its shattered economy, now in the fifth year of deep recession.

Euro zone finance ministers are due to decide whether to release the 130 billion euros ($170.57 billion) package during a conference call on Friday but they have already approved the bailout, subject to a private sector creditor agreement slated to go through later on Thursday.

($1 = 0.7622 euros)

(Reporting By Sarah Marsh; editing by Ron Askew)