Venture capital funding for open source vendors was down 50% in the second quarter compared to the same period last year. No great surprise there, but there was some good news as that figures was an increase on $45.4m raised in Q1.

According to our preliminary figures, there were 13 announced funding deals in the second quarter of 2009 worth $80.1m , compared to 20 in the second quarter of 2008, worth $160.8m.

Twelve of the deals announced in the second quarter of 2009 had a disclosed size, resulting in a combined total of $80.1m, and an average deal size of $6.7m. In the same quarter of 2008 there were 20 deals with a disclosed size resulting in a combined total of $160.8m, and an average deal size of $8m.

Total funding for the first half of the year stands at $125.5m, compared to $270.5m in 1H08, although as we pointed previously, the first half of last year was a record, as were Q1 and Q2 of 2008 individually.

(For more on the history and future of venture capital investment in open source vendors, see our recent CAOS report).

Early stage deals announced in the first quarter included a $15m round for Schooner, $5.5m for Eucalyptus, $2.5m for Opscode and $2m for Reductive Labs.

Later stage deals included $10m each for Likewise, OpenX and Vyatta, and $6m for Cloudera.

Larry Augustin previously predicted (PDF) $250m in 2009 from 30 deals, while I guessed there might be a few more deals and a lower average deal size.

At the halfway stage, the running total is $125.5m from 22 deals, so we’re both looking good to be half right.