The U.S. dollar was firm at a two-month high close to the 160 yen line early Monday in Tokyo as indicators point to the interest rate differential between Japan and the United States remaining wide. At 9 a.m., the dollar fetched 159.90-91 yen compared with 159.81-91 yen in New York and 158.76-79 yen in Tokyo at 5 p.m. Friday. The euro was quoted at $1.0686-0690 and 170.87-94 yen against $1.0689-0699 and 170.84-94 yen in New York and $1.0678-0680 and 169.54-58 yen in Tokyo late Friday afternoon. Stocks opened mixed, as technology issues tracked falls late last week in their U.S. counterparts, w…