HONG KONG (Reuters) -Hong Kong's bourse has booked its first profit growth in three quarters, marking record revenue and income for an April-June period as IPO and trading activity improved.

Net income for Hong Kong Exchanges and Clearing (HKEX) climbed 9% from a year earlier to HK$3.16 billion ($405 million) on a 7% gain in revenue.

The bourse said it had benefited from increases in trading and clearing fees as volumes across the cash, derivatives and commodities markets grew.

HKEX has been beset with challenges over the past few years, from Beijing's regulatory crackdown on a broad range of industries to rising U.S.-Sino tensions and lacklustre growth for the Chinese economy - all of which has greatly contributed to widespread disaffection with Chinese assets.

Its stock price is down some 15% for the year to date and was 1.9% lower in Wednesday's afternoon session after the results as investors noted the strong second quarter came after a particularly weak one.

But new Chief Executive Bonnie Chan said sentiment appears to be on the mend.

"Looking ahead, while macro-environment uncertainties persist, we remain cautiously optimistic about the outlook for the rest of the year," she said in a statement.

IPO activity which had been hit hard during the first quarter when Chinese stocks suffered a sharp sell-off is now showing "signs of warming", said Chan, who took the helm in March.

This was also helped by efforts by mainland Chinese authorities to expedite approvals of IPOs though deal values have been relatively small, all under $500 million.

Eighteen firms went public in Hong Kong during the second quarter compared to 12 in the first quarter, raising about 80% more in funds.

But some IPO initiatives have yet to get firmly off the ground. A plan to facilitate more specialist technology companies to make their debuts has attracted just two firms since new rules were introduced a year ago.

The exchange has also been making efforts to boost the attractiveness of its derivative offerings, announcing in April a major investment to develop its in-house derivatives platform.

($1 = 7.7906 Hong Kong dollars)