* Q1 net fell 7 pct, first decline since Q2 2009
* Auto unit's profit fell 20 pct in Q1
By Rieka Rahadiana and Andjarsari Paramaditha
JAKARTA, April 24 (Reuters) - Astra International, a Indonesian conglomerate with interests from banking to autos, said first quarter 2013 net profit fell 7 percent, the first decline in almost four years as economic growth slowed in Southeast Asia's biggest economy.
The results from Astra, Indonesia's largest listed company and seen as a bellwether of the economy due to its diverse businesses, underscore the weakening trend in the Indonesian economy as it grapples with slowing commodities demand.
It was the first profit decline since second quarter of 2009, putting an end to 14 consecutive quarters of growth, Reuters calculations based on Astra's published results showed.
Astra reported first-quarter net profit of 4.3 trillion rupiah ($442.23 million), compared with a net profit of 4.65 trillion rupiah a year earlier.
Domestic car sales in Indonesia grew 18.3 percent in the first quarter overall, but demand from January fell from 26.5 percent growth to only 9.1 percent in March.
Bank Indonesia sees gross domestic product to expand around 6.2 percent in January to March period of the year, lower than 6.3 percent in the same period last year.
The government is expected to hike fuel price for private cars next month, an effort to cut its hefty subsidy but will trim economic growth in line with rising inflation.