Mergers and acquisitions in the tech sector are booming, with 2014 on track to be the biggest year since 2000, when the market peaked before plunging, says tech research and advisory company 451 Research.

The third quarter saw $100 billion in announced spending worldwide on M&A in the technology, media and telecommunications sector, a record for a post-recession autumn quarter, the company said. In addition, 1,020 deals were announced, making the quarter the first since 2007 to go beyond 1,000 deals.

The $100 billion figure is up nearly 25 percent from the total logged in the third quarter of 2013, and it's almost twice as high as the total in the penultimate quarter of 2012.

In addition, the first three quarters of 2014 have seen M&A spending top $373 billion, more than the first three quarters of 2012 and 2013 combined and on track to total nearly $500 billion for the year, 451 said. (In part that's because of Facebook's $19 billion buy of texting app WhatsApp, announced in the first quarter, in February.) Spending in 2000 was nearly $600 billion.

In addition to the Facebook-WhatsApp hookup, the year's most noted M&A deals have included Apple's $3 billion purchase of headphone maker and streaming-music service Beats Electronics (announced during the second quarter, in May -- and Apple's biggest-ever acquisition); Google's $3.2 billion grab of Nest, a maker of smart-home products like thermostats and smoke detectors (announced in January); Facebook's $2.3 billion acquisition of Oculus VR, a maker of a virtual-reality headset (the first quarter, March); and Microsoft's $2.5 billion nab of Swedish firm Mojang, developer of the popular virtual-world game Minecraft (the third quarter, September).