LONDON, June 9 (Reuters) - Top U.S. and Chinese officials will sit down in London on Monday for talks aimed at defusing the high-stakes trade dispute between the two superpowers that has widened in recent weeks beyond tit-for-tat tariffs to export controls over goods and components critical to global supply chains.

London's benchmark index slipped on Monday after rounding off four weeks of gains, as caution prevailed ahead of much-awaited U.S.-China talks later in the day.