* Pretax profit up 5 pct at $10.2 bln, beats estimates
* Announces third share buyback worth up to $2 billion
* CEO says HSBC has one of the most "resilient capital ratios" (Adds further earnings details, executive comments, dividends, context)
HONG KONG/LONDON, July 31 (Reuters) - HSBC Holdings PLC on Monday said profit rose 5 percent in the first half of the year, beating analyst estimates, and announced its third share buyback in the past year on the back of a growing capital base.
Pretax profit reached $10.2 billion in the six months through June, from $9.7 billion in the same period a year earlier, HSBC said in a statement. The result compared with the $9.5 billion average estimate of analysts polled by the bank.
HSBC also announced an up to $2 billion share buyback, as it uses excess capital to offset the dilutive effect of shares paid out as dividends. It completed a previously announced $1 billion buyback in April.
Europe's biggest bank said it expects to commence the latest buyback shortly for completion in the second half of 2017.
The announcement takes the total of HSBC share buybacks since the second half of 2016 to $5.5 billion.
HSBC, like many global banks, spent the years up to the 2008 financial crisis building its empire. Recent years have seen it cut jobs and sell assets worldwide to shrink the group back to profitability and maintain dividend payouts in an era of stricter banking regulations.
"In the past 12 months we have paid more in dividends than any other European or American bank and returned $3.5 billion to shareholders through share buy-backs," Chief Executive Officer Stuart Gulliver said in HSBC's earnings statement.
"We have done this while strengthening one of the most resilient capital ratios in the industry."
The bank said its common equity tier 1 ratio - a measure of financial strength - was 14.7 percent at the end of June, from 14.3 percent three months prior, and 12.1 percent in the year-earlier period.
The ratio is set to increase further as the bank repatriates some $8 billion stuck at its U.S. subsidiary, following approval last year from the U.S. Federal Reserve.
HSBC has kept its dividend payout ratio higher than many peers in recent years, including last year when a slowdown in banks' earnings growth prompted rivals such as Standard Chartered PLC to withhold payments.
HSBC's dividends totalled $10.1 billion in 2016, $10 billion in 2015 and $9.6 billion in 2014. (Reporting by Sumeet Chatterjee and Lawrence White; Editing by Christopher Cushing)