* IT expert stole data on wealthy German and Dutch clients
* Man confesses to selling data on 2,700 Germans
* Middleman, a retired tax official, under investigation
* Switzerland under pressure to lift bank secrecy laws
ZURICH, June 28 (Reuters) - Swiss prosecutors have charged a German IT expert with selling client data from private bank Julius Baer in Zurich to the German tax authorities, they said on Friday.
The man, who was arrested last July and is charged with breaching banking laws, industrial espionage and money laundering, had confessed and would therefore face a shorter trial. They dropped proceedings against his wife.
An accomplice, identified only as a retired German tax inspector, was under investigation, the prosecutors said in a statement. A Swiss request for German legal assistance in the investigation had gone unanswered, they said.
Julius Baer Chief Executive Boris Collardi went public in a newspaper interview in August about the data theft, which he said had been discovered due to tighter controls following similar incidents. The bank declined to comment on Friday.
Strict bank secrecy, which helped Switzerland build a $2 trillion offshore industry, is under fierce attack as cash-strapped governments get tough on tax evasion, with Swiss banks under investigation in Germany, France and the United States.
Julius Baer agreed in 2011 to pay German tax authorities 50 million euros ($65 million) to close a tax investigation, but is still under investigation in the United States for helping wealthy Americans evade taxes through secret Swiss accounts.
Prosecutors said the IT expert, who they did not name, collected data on wealthy German and Dutch clients from various Julius Baer systems between October and December 2011, as agreed with the German middleman.
He sent 15 emails from his work computer to his private account with attachments containing client names, addresses, account numbers, account balances and currencies, they said.
He filtered the data for German clients with more than 100,000 euros, Swiss francs, pounds sterling or U.S. dollars and sent a sample of the information to his accomplice, who he met later in Berlin in February 2012, the statement said.
In Berlin he handed over data on 2,700 more German clients to be transferred to the German tax authorities and agreed on payment of 1.1 million euros, although prosecutors said they could only recover 140,000 euros from his accounts.
The man sent his accomplice data on Dutch clients of Julius Baer in May and June of last year, which he hoped to sell to Dutch authorities for 400,000 euros, but they turned him down.
Germany and Switzerland struck a deal last year aimed at allowing Swiss banks to levy tax on Germans clients without revealing their identities, but it was overturned by the centre-left opposition in the upper house of parliament.
The German state of North Rhine-Westphalia says it has bought client data from the Switzerland-based operations of Credit Suisse and Julius Baer, as well as Merrill Lynch and Coutts, a wealth manager owned by Royal Bank of Scotland.
Switzerland issued arrest warrants last year for three North Rhine-Westphalia civil servants, accusing them of industrial espionage for buying the bank details of German tax evaders.