MELBOURNE, March 22 (Reuters) - London copper climbed off its lowest in three months on Thursday after the U.S. Federal Reserve signalled a slower pace of rate rises this year, which weighed on the dollar. FUNDAMENTALS * London Metal Exchange copper traded at $6,838 a tonne by 0230 GMT, extending a small recovery from the previous session, when prices plumbed a three month trough at $6702 but finished up half a percent. * Shanghai Futures Exchange copper rose 0.9 percent to 51270 yuan ($8,117) a tonne. * The U.S. Federal Reserve raised interest rates on Wednesday and forecast two more hikes for 2018 in its first policy meeting under new Fed Chairman Jerome Powell. * President Donald Trump will announce tariffs on Chinese imports on Thursday, a White House official said, in a move aimed at curbing theft of U.S. technology and likely to trigger retaliation from Beijing and stoke fears of a global trade war. * Swiss prosecutors confirmed on Wednesday they were investigating whether miner Rio Tinto paid bribes linked to the landmark Oyu Tolgoi copper-gold mine. * Japanese manufacturing activity expanded at a slower pace in March than the previous month as growth in new orders and output moderated, in a sign that the economy may be losing a little momentum. * Among other metals, LME aluminium rallied more than 1 percent, breaking back above the 200-day moving average after closing below the key technical level for two sessions in a row. * Shfe aluminium however was flirting with its weakest levels in 14 months, around 13,820 yuan, with more China production expected to come on stream in coming weeks after the expiration of the country's winter pollution controls.