Indonesia's advertising expenditure in the first half of this year saw the most growth in four years, driven mostly by increased spending from mobile phone operators as well as political party ads for regional elections, Bloomberg reported Monday.

Total spending reached 19.56 trillion rupiah (US$2.1 billion) in the six months ending June 30, which was up 24 percent, the fastest rise since a 50-percent increase in the first half of 2004, according to Nielsen Media Research Indonesia.

Spending by political organisations may boost ad spend in the second half and early next year even further, before general elections in April. Parties competing in regional polls increased expenditure by more than six-fold in the first half, according to Nielsen's data. Another catalyst was the price wars among mobile-phone providers, which led to a tripling of ad spending in this period by Excelcom, the third-largest cellular-phone operator in the country, Bloomberg reported.

“There will be a lot more spending by political organisations,” Winda Ekariany, a spokeswoman for Nielsen, told Bloomberg. “That will drive ad spend.”

Spending by political organisations and the government was up 79 percent in the first half, and reached 769 billion rupiah. In March 2004, a month before general elections that year, political parties spent 131.1 billion rupiah, according to Nielsen.

Mobile phone companies spent 1.98 trillion rupiah in the first half, 57 percent more than the same period a year previous, according to Bloomberg.