Oct 8 (Reuters) - Citadel Securities said on Thursday it would acquire the NYSE market-making business of rival IMC Financial Markets, in a deal that would solidify its presence at the New York Stock Exchange.

The move will make Citadel Securities, which oversees daily trading in more than 1,500 NYSE-listed securities, the largest designated market maker (DMM) at the exchange, it said in a statement.

DMM, formerly known as "specialists", operate both manually and electronically to facilitate price discovery during market openings, closings and during periods of substantial trading imbalances or instability for thousands of NYSE-listed stocks.

IMC has been a DMM on the NYSE since 2014, when it acquired Goldman Sachs' business, the company said.

"The decision to sell our DMM business at this time is in line with IMC's growth strategy, which focuses on our core strengths - market making, advanced technology and deep liquidity," said Sunny Khiani, managing director of IMC's U.S. operations.

The financial terms of the deal, which is expected to close in the fourth quarter, were not disclosed. (Reporting by Abhishek Manikandan in Bengaluru; Editing by Anil D'Silva)