LONDON  - The dollar dipped against the euro and the yen as the foreign exchange market awaited quarterly earnings from US banking titan Citigroup. In morning deals, the European single currency firmed to 1.5857, from 1.5850 in New York late on Thursday. The euro had struck a historic peak of $1.6038 on Tuesday, owing to stubborn worries about the US financial sector. That beat the previous high of 1.6019 set in April. Against the Japanese currency on Friday, the dollar eased to 106.35 yen from 106.37. In a separate development, the Czech koruna pushed through the psychological 23.00 koruna/euro barrier to set a new record of 22.999 koruna/euro on Friday as the currency continued to be sought as a refuge from weakening equities. The koruna also reached a new record of 14.50 koruna/dollar, due to the same type of speculative buying, analysts said. In early London trading on Friday, the euro changed hands at 1.5857 dollars against 1.5850 late on Thursday, at 168.69 yen (168.61), 0.7961 pounds (0.7918) and 1.6181 Swiss francs (1.6166). The dollar stood at 106.35 yen (106.37) and 1.0200 Swiss francs (1.0197). The pound was at 1.9936 dollars (2.0014).