Pericles Panagopoulos has been described as a shipping visionary
A Greek shipping magnate has been kidnapped at gunpoint near his home on the outskirts of Athens, police say.
Pericles Panagopoulos was abducted, along with his driver, after their car was deliberately blocked in the seaside suburb of Kavouri.
The two men were bundled into another vehicle, though the driver was released a short while later.
Mr Panagopoulos, who is 70 and said to be in poor health, was the founder of Greece's largest ferry company, Attica.
Police said the kidnapping appeared to have been carried out by three armed men.
Mr Panagopoulos was taken away in a dark van, which was abandoned about 15km (10 miles) away, police said.
The alarm was raised by a builder, who saw the kidnappers hustle their victim into another getaway vehicle. The chauffeur was left handcuffed in the van.
Mr Panagopoulos has been described as a shipping visionary, says the BBC's Malcolm Brabant in Athens.
He sold a cruise line in 1990 for $300m (225m euros, £200m) and then made another fortune by establishing Superfast Ferries, which slashed the voyage times between Greece and Italy, and captured the bulk of the market of container lorries and holiday traffic.
Kidnapping has recently reappeared as a criminal tactic in Greece.
Last year the aluminium tycoon George Mylonas spent two weeks in captivity but was released after his family reportedly handed over a ransom of 12m euros.
And a cardiologist snatched near Athens in December last year has still not been found. Police fear he may have been seriously hurt, or even killed, during the abduction.