Radvision, an Israel-based developer of products and technologies for unified visual communications, has posted revenues of $20.8m for the first quarter of 2011.

The operating loss for the first quarter of 2011 decreased to $3.5m compared with an operating loss of $4.3m in the first quarter of 2010.

The company posted net loss of $3.34m, or $0.18 per diluted share, for the first quarter ended 31 March 2011, compared with a net loss of $4.4m, or $0.22 per diluted share, in the first quarter of 2010.

Revenue from technology business unit increased to $4.8m from $4.0m for the same period last year while revenue from video business unit decreased to $15.9m for the first quarter 2011, compared to video business revenue of $16.8m.

Radvision CEO Boaz Raviv said their first quarter revenues were in line with their revised forecast but below their original expectation.

"With our Technology Business Unit revenues 21% better than expected, the shortfall came in our Video Business Unit, primarily due to Cisco revenues that were $3m lower than expected, as we announced previously," Raviv said.

"Excluding Cisco, our VBU revenues increased 59% from the first quarter of 2010, with substantial growth in all regions. Our successful introduction of endpoints, the proven advantages of our infrastructure offering, and our progress in expanding our channel network remained the drivers of our core VBU business."