* Germany says gas market is open to all participants
* U.S. official tells Bild: LNG is coming to Germany
* Wants to challenge Russia's dominance of German gas imports (Adds German government spokeswoman)
BERLIN, Sept 17 (Reuters) - Germany's gas market is open to all market participants, a government spokeswoman said on Monday after a newspaper reported that U.S. firms expect to start delivering liquefied natural gas (LNG) to Germany in four years at the latest.
Deputy U.S. Energy Secretary Dan Brouillette told Bild that LNG deliveries from U.S. companies would challenge Russia, which now accounts for 60 percent of German gas imports.
"U.S. liquefied natural gas is coming to Germany. The question is not if, but when," Brouillette told the mass circulation daily Bild in an interview published on Monday.
Responding to the report, German government spokeswoman Martina Fietz told reporters in Berlin: "The German gas market is basically open to all market participants."
She added that it was up to the traders and distributors who are active on the German gas market to decide on specific supply relationships.
U.S. President Donald Trump in July accused Germany of being a "captive" of Russia due to its energy reliance and urged it to halt work on the $11 billion, Russian-led Nord Stream 2 gas pipeline that is to be built in the Baltic Sea.
Germany rejects this charge and says it is open to diversifying its energy sources, but says sales will ultimately be determined on economic grounds.
Brouilette, who acknowledged U.S. LNG would cost more, said the entry of U.S. suppliers onto the German market would effectively set a price ceiling for Gazprom, the Russian state energy company that leads the Nord Stream 2 consortium, and other suppliers.
"Because U.S. LNG is here, Gazprom cannot demand whatever it wants," Brouillette, who met with German business executives in Berlin last week, told the newspaper.
U.S. Ambassador Richard Grenell told the newspaper that Chancellor Angela Merkel had assured Trump personally that Germany wanted to purchase U.S. LNG supplies.
The debate about German LNG imports has flared up in recent weeks as operators and the government have shown an interest in diversifying away from pipeline gas arriving from Russia, Norway and the Netherlands.
Qatar has also expressed interest in selling LNG to Germany.
German firms are considering building an LNG terminal in Germany, as gas demand rises in Europe and the Netherlands, one of Germany's crucial suppliers which is winding down its giant Groningen field and plans to close it in 2030.
Reporting by Andrea Shalal Editing by Edmund Blair and David Evans