The chief executive of Lufthansa expressed frustration on Wednesday over the United States' restrictions on foreign ownership of airlines.

Lufthansa holds a 19 percent stake in JetBlue Airways, but the US Congress has resisted pressure to lift a 25 percent cap on foreign ownership of US airlines.

"Yes, we would have loved to do more (with JetBlue) but we are limited," Lufthansa chief executive Wolfgang Mayrhuber said in New York.

Asked if Lufthansa expected to ever increase its stake in JetBlue, Mayrhuber said: "We leave it open. That's the current regulation -- nobody should be afraid of foreign direct investment."

Mayrhuber said a lot of investments by American companies around the world were not limited and that fresh capital would be of benefit to the United States.

European airlines have been hoping the second stage of the US-EU Open Skies agreement, now under discussion, would force the United States to lift foreign ownership restrictions on its airlines by 2010.

President George W. Bush supported that goal, but US union groups and Democrats have opposed the idea, fearing it would mean job losses for financially weak US airlines.

Mayrhuber said the United States was the driver of foreign direct investment around the world and benefited a lot from it, so it was curious it placed restrictions on foreign investment in US airlines.

"It does not mean we have a lot of cash and want to buy everything here, but it's curious -- we can re-regulate or stay where we are and not move at all," said Mayrhuber, who spoke at a Yale Club luncheon and afterward to reporters.

"If we believe this is a global industry... why should we then limit ourselves in areas like ownership?" he asked.

Asked if Lufthansa is considering investing in another US airline, Mayrhuber replied: "Not at the moment."

Lufthansa has been leading the pack in European airline consolidation and is currently the exclusive bidder for state-controlled, loss-making Austrian Airlines. A deal is expected within a month.

"It's no secret we talked to them and put an offer in," Mayrhuber said.

But he added: "We will only be interested if we have a fair share of the debt... we would be willing to do it, but we will not take all the baggage."

Lufthansa is demanding that it assume only half of Austrian Airlines' EUR900 million euros debt.

Asked if Lufthansa was still interested in a tie-up with Italian carrier Alitalia, Mayrhuber said: "They make the decision, not us."

The Italian government said on Wednesday it agreed to sell Alitalia's assets to a group of Italian businessmen at an improved price.