TOKYO, Oct. 9 (Kyodo) - Domestic wholesale prices in Japan dropped 1.1% in September from a year before for the 12th consecutive month of decline, the Bank of Japan (BOJ) said Tuesday. The domestic wholesale price index came to 95.2 for the reporting month against the base of 100 for 1995, the BOJ said. The index edged down 0.2% from the previous month. Prices of petroleum and coal products grew 6.6% from a year before but those for steel, nonferrous metal and electrical equipment fell 3.4%, 1.2% and 5.4%, respectively, the BOJ said. Export prices, measured in yen terms, grew 2.6% from a year before due to a stronger yen, but dropped 2.1% from the previous month, the central bank said. Import prices, also measured in yen terms, increased 3.5% from a year earlier but declined 2.6% from a month earlier.