By Henning Gloystein and Jessica Jaganathan SINGAPORE, Aug 8 (Reuters) - U.S. exports of liquefied natural gas (LNG) to China in July fell to their lowest level in a year and are expected to decline further as the Sino-U.S. trade dispute forces utilities to seek alternative supplies. In an escalating trade dispute, China last week said it may slap a 25 percent import tariff on U.S. LNG supplies in retaliation to a raft of duties on Chinese goods that U.S. President Donald Trump has announced since June. "The import tax will make U.S. exports of LNG uncompetitive," energy research group Bernstein said in a note this week. Traders said Chinese buyers were already seeking alternatives. "The Chinese are already indicating that they would prefer not to take U.S. cargoes for any new spot deals," said a Singapore-based energy trader who deals with Chinese LNG importers. He declined to be identified because he was not authorised to speak publicly about commercial operations.