HONG KONG—For China's biggest broker and underwriter, the toughest IPO of the year may have been its own.

Citic Securities Co struggled in its public trading debut Thursday in Hong Kong amid market turmoil and skepticism about Chinese stocks. The broker's shares, which were priced near the low end of what was expected, promptly tumbled 10% when trading began and bounced back only when their underwriters snapped up shares.

The broker's shares ended the day right at their IPO price of HK$13.30 ($1.71), even though the market surged 5.7 percent, its biggest gain in two and a half years.

Citic Securities had plowed ahead with its $1.7 billion IPO—the world's biggest since August—even as the Hong Kong market fell 12.5 percent in the past month and other companies pulled their offerings.

The deal was completed largely because it was half sold before the IPO. Major investors, including sovereign-wealth fund Kuwait Investment Authority and Singapore state investment company Temasek Holdings Pte Ltd, bought 50 percent of the deal, and the lead bankers had agreed to buy most of any unsold shares.

But individual investors, nervous about market volatility, shunned the deal. While 5 percent of the deal was slated for retail investors, just 0.4 percent was sold, even though the portion of the deal reserved for institutional investors was two times oversubscribed. To draw in investors, Citic Securities, whose parent Citic Group is a State-owned mining-to-financials conglomerate, had priced the IPO at near the bottom of a HK$12.84-HK$15.20 price range.

Citic Securities' listing prospectus said the firm was the top underwriter for equity and debt offerings in China last year, ahead of China International Capital Corp. It also said the firm was No 1 in the brokerage business, with more than US$1.69 trillion in trading turnover last year, ahead of Huatai Securities.

But weak markets, particularly in Shanghai, where Chinese A-shares trade, increased concerns about Citic's prospects. The Shanghai Composite Index, which has been closed for the Golden Week holidays this week, fell 6.7 percent in September.

"Even though Citic Securities is a market leader and has a large client base, investors are concerned it will suffer from the weakness in the A-share market, as brokerage commissions are one of its biggest sources of revenues," said Castor Pang, Hong Kong-based head of research at Core Pacific-Yamaichi, a Taiwan brokerage.

On Thursday, Asian stocks rebounded, helped by an overnight 1.2 percent gain in the Dow Jones Industrial Average on better-than-expected US jobs data. In addition to the surge in Hong Kong's Hang Seng Index as the market returned from a holiday Wednesday, Japan's Nikkei Stock Average climbed 1.7 percent, Australia's S&P/ASX 200 tacked on 3.7 percent, and South Korea's Kospi climbed 2.6 percent.

Despite the Hang Seng's jump, the index is down 23.5 percent since August.

Citic Securities' Hong Kong IPO is the biggest globally since Spain's third-largest bank, Bankia SA, raised $4.4 billion in July ahead of a listing in Madrid. In August, a downgrade of US credit ratings by Standard & Poor's rattled markets world-wide and led to several deals being scrapped or cut.

Deals that have been put off due to worries about the markets and China's economic growth in the past month include the $3.3 billion Hong Kong IPO by Chinese crane maker Sany Heavy Industry Co, controlled by Chinese tycoon Liang Wengen, and the $1.2 billion deal by its rival XCMG Construction Machinery Co.

Chan Ka-keung, Hong Kong's secretary for financial services and the treasury, said during Citic Securities' listing ceremony at the Hong Kong stock exchange on Thursday that this isn't "the kind of market where IPOs are easy to do."

Among companies slated to launch IPOs in the next few months in Hong Kong is China's third-largest life insurer by premiums, New Life China Life Insurance Co, which is looking to raise up to $4 billion. Hong Kong telecom operator PCCW Ltd. is planning to raise up to $1.28 billion from the listing of a business trust.