(Reuters) - Euronext NV (>> Euronext) said September was its most active month in terms of average daily transaction value since 2008 as uncertainty over the U.S. Federal Reserve interest rate hike and concerns of a slowdown in China weighed on stock markets.

Euronext, a pan-European exchange operator, said average daily transaction value on its cash order book rose 35 percent to 8.07 billion euros (£5.96 billion) last month from a year earlier.

September was the culmination of a "volatile" quarter, said Lee Hodgkinson, head of markets and global sales at Euronext.

Trading volumes in August and September were boosted by the slowing Chinese economy and its impact on emerging markets and commodities, and the U.S. Fed interest rate decision, Hodgkinson told Reuters.

"European economic indicators have been reasonably positive with the major surveys providing some level of reassurance about the eurozone growth momentum. September has seen some important corporate activity, most notably the Anheuser-Busch InBev (>> ANHEUSER-BUSCH INBEV) and SABMiller Plc (>> SABMiller plc) bid," Hodgkinson said.

Euronext - the operator of bourses in Paris, Amsterdam, Brussels, London and Lisbon - said that Sept. 18 was the second-most active day of the year with trading of 18.1 billion euros.

Average daily transaction value for ETFs more than doubled to 614 million euros, compared with September 2014, the exchange operator said.

However, foreign exchange spot volumes in September were dull on the EBS platform, owned by Interdealer broker ICAP Plc (>> ICAP plc).

An ICAP spokeswoman told Reuters that forex volatility remained low in the main trading currencies in September as markets remained tentative ahead of the Fed meeting and the lack of a catalyst given there was no rate increase.

The U.S. Federal Reserve kept interest rates unchanged on Sept. 17 in a bow to worries about the global economy, financial market volatility and sluggish inflation at home.

Average EBS volumes dropped to $89.4 billion (£58.8 billion) per day in September, down 11 percent from the previous month and 24 percent from a year ago, said ICAP, which matches buyers and sellers of bonds, swaps and currencies.

EBS is the main venue for banks and other major institutions to trade the euro <.EUR=>, yen <.JPY=> and Swiss franc against the dollar.

Euronext stock was up 1.8 percent, while ICAP shares were up 1.6 percent at 0941 GMT.

(Reporting by Noor Zainab Hussain in Bengaluru; Editing by Gopakumar Warrier)

By Noor Zainab Hussain

Stocks treated in this article : ANHEUSER-BUSCH INBEV, SABMiller plc, ICAP plc, Euronext