CoStar Group Inc. is acquiring LoopNet.com, an online commercial real estate marketplace, in a transaction valued at $860 million, Inman News reported on Wednesday. This acquisition will reportedly result in a single database of 2 million active listings and more than $300 million in annual combined revenue.

Both companies’ boards of directors have approved the merger, which is expected to close by the end of 2011.

CoStar and LoopNet have been at the cutting edge of innovation in their respective businesses, and we believe the two companies will be even stronger together, said Richard Boyle, Chairman and CEO of LoopNet. This transaction combines the capabilities and best practices of two successful and very complementary companies. We are excited about the possibilities that can be created together.

While CoStar has “revolutionized how the industry researches commercial real estate,” LoopNet has changed the way the industry markets itself, according to Andrew C. Florance, CoStar Group's Founder and CEO.

“We believe that the combination of our two outstanding and complementary companies will lead to even more innovation and greater efficiencies by creating the premier Internet solution for the commercial real estate industry,” said Florance in a conference call announcing the agreement. “We expect the benefits to our customers and ultimately our shareholders to be very significant.