WASHINGTON – Nasdaq Stock Market Inc. will cut its execution prices beginning November 1 in a competitive move aimed at driving more transactions to its system.

The price cut, which requires SEC approval, won’t have a material effect on Nasdaq’s earnings, the stock market said yesterday.

A Nasdaq official said because it has different pricing tiers for customers, there isn’t one flat percentage rate that costs will decline. Instead, the discounts depend on how often customers use the system, with some low-frequency traders seeing little to no change, while those who trade most frequently will receive the deepest price cuts.

“We expect people to change their behavior to get to that lower tier,” said Nasdaq’s executive vice president for transaction services, Christopher Concannon, during a telephone interview.

The cut comes at a time when trade volume has been tepid for Nasdaq and all its rivals, including other exchanges like the New York Stock Exchange and ECNs like Instinet Group Inc. It is also coming several months before Nasdaq plans to enhance its execution offerings by providing traders with a “virtual book” that combines the liquidity of Nasdaq with Brut ECN, which it acquired in September. Although traders can access both sources of liquidity now, there isn’t yet a centralized book to view them at once.

Mr. Concannon said under the new pricing structure, if customers use its new smart-order router, a Brut tool that allows traders to access outside pools of liquidity at other ECNs and markets, they could get lower per-share transaction prices than if they accessed those markets directly.

Nasdaq had been grappling with increasing competition from ECNs for a year when it decided last spring to buy Brut. Prior to that, Nasdaq had built Super Montage, a trading system meant to compete with ECNs.