* Q1 net profit 51.9 bln yen vs 61.2 bln year-ago
* Wholesale division pretax profit falls 57 pct y/y
* Nomura hit by fall in bond trading (Adds details of wholesale, international and retail units)
TOKYO, Oct 30 (Reuters) - Nomura Holdings Inc posted a wider-than-expected drop in quarterly profit as weakness in its wholesale division, that was hit by a drop in fixed income trading, offset growth in the company's resurgent retail business.
Japan's biggest brokerage and investment banking group said in a statement that its July-September net profit came in at 51.9 billion yen ($457 million), versus 61.2 billion yen a year ago, falling for the first time in five quarters.
That was also below an average estimate of 60.5 billion yen from two analysts polled by Thomson Reuters.
At Nomura's wholesale unit that serves corporate and institutional clients, pretax profit fell 57 percent to 17 billion yen, the lowest in a year, as fixed income trading in the Americas and Europe, Africa and the Middle East declined.
That mirrored a wider trend felt across Wall Street banks, and almost wiped out pretax profit at Nomura's international arm, which fell 96 percent to 0.9 billion yen, highlighting the firm's vulnerability to fluctuations in global markets.
Pretax profit at Nomura's domestic-focused retail unit grew 77 percent to 25.5 billion yen, boosted by individual investors piling into high-profile share sales such as the 1.3 trillion yen public offering by Japan Post Holdings - the world's second biggest this year.
The retail business has returned to growth, posting its second consecutive quarter of gains, after reporting its lowest profit in five years in the twelve months ended March.
Nomura said it would buy back up to 1.8 percent of its stock for as much as 50 billion yen. ($1 = 113.6600 yen) (Reporting by Thomas Wilson; Editing by Himani Sarkar)