UPDATE 2-Merkel's party wants higher taxes on domestic flights, party document shows

(Adds reaction from Lufthansa)

By Markus Wacket

BERLIN, Sept 13 (Reuters) - Seeking to tackle climate change, Germany's conservatives want to increase taxes on domestic flights and reduce the cost of long-distance train tickets, a party document seen by Reuters on Friday showed.

The German government - made up of Chancellor Angela Merkel's conservatives, their Bavarian sister party CSU and the Social Democrats (SPD) - is expected to present a far-reaching package of climate protection measures on Sept. 20.

The tax for domestic flights is now 7.40 euros ($8.21).

"We want to double this ticket tax for all domestic flights and triple it for short-haul domestic flights under 400 kilometers," said a party document that the board of Merkel's Christian Democrats (CDU) is due to review on Monday.

The document, called "Climate-friendly Germany - using innovations as we head into the future", showed that the party also wants to make long-distance rail travel cheaper by reducing the value-added tax on train tickets.

A spokeswoman for Germany's flagship airline, Lufthansa , said on Friday that air transport faced more international competition than other transport and such national measures could result in traffic shifting to regions where levies are smaller or non-existent.

"Such a high burden for domestic flights disproportionately affects German airlines and deprives them of money for modern airplanes and climate-friendly technologies," the spokeswoman said of the CDU proposal.

She added that domestic flights only accounted for 0.3% of Germany's overall carbon dioxide emissions and it was questionable whether such measures would have any tangible ecological impact.

The document also said a premium worth several thousand euros should be introduced to encourage people to scrap old, inefficient heating systems so that climate targets for buildings can be achieved.

($1 = 0.9010 euros) (Additional reporting by Ilona Wissenbach in Frankfurt, writing by Michelle Martin; editing by Paul Carrel, Larry King)