Unix giant Sun Microsystems has signed a definitive agreement to acquire advanced server technology company Kealia.

The deal will see Andy Bechtolsheim, a co-founder of Sun Microsystems and vice president of technology from 1984 to 1995, rejoin the firm.

Sun chairman, chief executive officer and president Scott McNealy, said in a statement: "We started the company together while we were at Stanford University over 20 years ago and both of us could not be more excited about working together again.

"The return of employee number one is 'back to the future' for Sun Microsystems and marks the start of a new wave of innovation at the company. Stay tuned."

Bechtolsheim added that he was "very excited" about returning to Sun.

Under the terms of the agreement, which is still subject to the usual closing conditions, Sun will acquire Kealia in a stock-for-stock merger.

The acquisition is expected to close during the third or fourth quarter of Sun's fiscal year 2004.

Kealia will become the advanced systems technology group within Sun's Volume Systems Products organisation, headed by executive vice president Neil Knox.

Bechtolsheim will return to Sun as senior vice president and chief architect within the volume systems products group, reporting to Knox, and will also be a member of Sun's executive management group, led by McNealy.