NEW YORK, June 23 (Reuters) - Beacon Capital Markets said on Tuesday it will offer electronic trading of asset-backed securities for the first time, beginning next month, with an expansion of its existing trading platform.

Asset-backed securities, commercial mortgage-backed securities and riskier residential mortgage-backed securities -- the risky debt securities at the heart of the financial crisis -- will begin trading on July 10, said Rob Barsky, chief operating officer and a founder of Beacon.

Beacon currently provides electronic trading for about 51 clients in mortgage bonds guaranteed by Fannie Mae, Freddie Mac and Ginnie Mae. It expects at least that many clients to participate in trading of the riskier securities, including MBS issued outside the government-guaranteed umbrella, Barsky said.

Increased trading of ABS amid U.S. government programs to support new lending in consumer and mortgage debt -- including the Term Asset-Backed Securities Loan Facility -- should give rise to demand for the electronic platform, he said. The platform matches sellers with buyers, but the trade price is not revealed.

"The TALF program has stimulated primary issuance and that has brought people back to the market, said David Audley, one of Beacon's founders. (Reporting by Al Yoon; Editing by Leslie Adler)