* Daily oil output 10.34 mln bpd, up 0.6 percent from July 2011
* Total gas output 45 bcm, down 4.5 percent from July 2011 (Adds change from year ago, background on West Siberian decline)
MOSCOW Aug 2 (Reuters) - Russian oil output, the world's largest, rose to 10.34 million barrels per day (bpd) in July from 10.32 million bpd in June, keeping it just ahead of its nearest rival, Saudi Arabia, Energy Ministry data showed on Thursday.
Saudi Arabia pumped 10 million bpd in July, a Reuters survey showed. Russia's post-Soviet record was 10.36 million bpd.
In tonnes, the ministry said total crude production stood at 43.74 million in July.
Output growth was less than one percent compared to July 2011, and Russian oil companies are struggling to maintain even these lacklustre growth rates as their main fields in West Siberia, the workhorse of the Soviet oil industry, decline.
Russian oil firms raised output by nearly 50 percent between 2002 and 2010, and are experimenting with expanded horizontal drilling and multi-stage hydraulic fracturing - technologies which aided the shale boom in the United States - to squeeze more barrels out of the old province, in addition to development of new fields.
Daily gas production stood at 1.45 billion cubic meters (bcm) in July, down from 1.54 bcm in June. Total output for the month was 45 bcm, down 4.5 percent from July 2011 as Russian export monopoly Gazprom faces weak demand in its main export market, Europe.
It had been expected to rise with the planned June launch of Gazprom's giant Bovanenkovo field, but the launch was delayed to October. (Reporting by Katya Golubkova; editing by Melissa Akin and James Jukwey)