U.S. venture capital firms raised $4.1 billion last quarter, down almost 18 percent from the same period in 2012, according to data from the National Venture Capital Association and Thomson Reuters released on Monday.

The dollar amount was down from the almost $5 billion raised in the third quarter of 2012, when venture-backed investments in technology startups soared.

"The gradually improving IPO market, along with better quality exits on the M&A side, are signaling to limited partners that venture funds can still yield attractive returns," said John Taylor, the association's head of research.

"Smaller fund sizes are not surprising as venture capitalists are looking to invest in less capital-intensive sectors and are focused on deploying capital more efficiently."

The bulk of the cash was raised by a handful of venture firms amassing outsized funds. Greylock raised $1 billion, becoming the first U.S. venture capital fund to cross that threshold this year for a single fund. Sequoia Capital raised $552.9 million for its U.S. Venture Fund XIV, plus $391.4 million for Sequoia Capital China and $227 million for Sequoia Capital Israel V.

Venture-capital fundraising for the first nine months of the year totaled $11.6 billion, well off the $16.2 billion amassed at the same point in 2012.

(Editing by Andre Grenon)