Google is preparing a spoiler to slap down Microsoft's bid to acquire online advertising broker DoubleClick, according to reports.

Tuesday's Wall Street Journal cites the trusty "people familiar with" the sell-off talks, and links Google with a $2bn-plus swoop on the private equity-owned outfit. Google has been competing with DoubleClick since it started brokering banners, as well as its core text ads, in 2005.

Google never comments publicly on acquisition talks, but it would perhaps be more surprising if it didn't have a seat at the table. Last week the paper said Microsoft was exploring coughing the cash for DoubleClick, which netted revenues of $150m last year, as were Yahoo! and AOL.

Assimilating DoubleClick would make Google's lead in online ads nigh-impregnable. It would also provide a convenient boot to stomp the embryonic buzz surrounding Yahoo!'s new Panama contextual ad platform, which the firm's boss Terry Semel has been talking up ahead of delivering its first results.

The Wall Street Journal's source said bidding had reached $2.6bn on Friday, which would hardly trouble Google's accountants...or Microsoft's, for that matter. ®