Apparently, UPEK really wants to be a public company. It put in its IPO paperwork back in mid-2007, only to pull it in March 2008. Unlike other former filers, however, the biometric security vendor hasn’t dusted off its S-1 in an attempt to hit the public markets. (In the past week, both Convio and GlassHouse Technologies have re-filed to go public.) Instead, UPEK wants to get on the Nasdaq by picking up a rival that already trades there.

UPEK lobbed an unsolicited offer at AuthenTec on Friday that basically envisioned consolidating the two companies, which make fingerprint sensors, into a single business. Equity ownership would be evenly divided between the two sides. For its part, AuthenTec has been a public company since mid-2007, although its shares have lost some three-quarters of their value in that time. On Monday, AuthenTec, advised by America’s Growth Capital, rejected UPEK’s ‘highly dilutive and speculative transaction.’