* Q2 net profit 589 mln riyals vs 502.1 mln riyals - statement
* Boosted by associates' performance, domestic economy
* Lending up 46 percent yr-on-yr at end-June (Adds detail, context)
DUBAI, July 14 (Reuters) - Commercial Bank of Qatar (CBQ), the Gulf Arab state's second-largest lender by assets, beat analysts' forecasts with a 17.3 percent rise in second-quarter profit on Tuesday, on the back of its associates' performance.
The five largest Qatari banks have now reported earnings, painting a generally positive picture of the Gulf state's banking sector.
Qatar National Bank, the largest lender in the Gulf Arab region, Qatar Islamic Bank and Masraf Al Rayan all reported higher earnings, while Doha Bank's profit slipped marginally.
CBQ posted a net profit of 589 million riyals ($161.8 million) for the three months to June 30, it said in a statement, ahead of the 495.2 million riyals average forecast of seven analysts polled by Reuters.
The bank attributed the profit gain to a strong local economy and growth at its associates, which helped offset stronger domestic competition and the impact of volatility in the Turkish lira.
CBQ owns Alternatifbank in Turkey and a stake in United Arab Bank in the United Arab Emirates. It also owns 34.9 percent of National Bank of Oman, which reported a 21.4 percent jump in second-quarter net profit on Tuesday.
CBQ's loans and advances stood at 72.6 billion riyals at the end of June, up 4.6 percent from a year earlier.
Overall Qatari credit grew in February at the slowest pace since at least 2007, according to central bank data. The most recent data showed growth slowed to an annual 8.2 percent in April from 9.5 percent in March.
Credit growth in the Gulf state has been one of the main drivers of banks' expansion in recent years as the government has spent in preparation for Qatar's hosting of the soccer World Cup in 2022. Delays to some major infrastructure projects and a move by the government to fund more schemes directly, rather than using banks, has contributed to a cooling in credit growth.
CBQ's deposits stood at 64.1 billion riyals as of June 30, up 7 percent year-on-year.
$1 = 3.6413 Qatar riyals Reporting by Tom Arnold; Editing by David French and Susan Fenton