Japan's service industry activity index fell 0.8 percent in July from the previous month due to lackluster sales of software and, apparently, weak electricity demand caused by bad weather, the government said Thursday.

The tertiary industry index -- a measure of demand for services -- stood at a seasonally adjusted 105.5 against the base of 100 for 2000, after registering a 0.9 percent rise in June to 106.4, the Ministry of Economy, Trade and Industry said in a preliminary report.

Of the 11 sectors the report covered, activity indexes declined in eight sectors, with information and communications contributing the most to the drop.

A METI official said orders for computer software products, excluding games, slipped in the reporting month following robust demand in June. Supposedly cool weather also pushed down demand for electricity and hurt retail sales of air conditioners, the anonymous official added.

The remaining three sectors -- education, medical services and finance -- posted gains, according to the report.