The 12-story, 236,000-sf office building stands at 555 AntonBlvd. It was leased for years to Unocal 76 Products before theenergy giant was acquired by Tosco Corp., which then moved most ofthe jobs out of state and left the building vacant.

The current owner, Denver-based Amstar Ltd., bought the complexfrom Bank of America for about $40 million in 1998. After makingroughly $30 million in improvements, the complex was leased to along list of tenants that include anchor BMC Software, Tickets.comand Epoch Internet.

Though the building is virtually fully leased, the fact thatdot-com tenants occupy more than half the space may hurt theproperty's marketability. "Buyers want real estate here, but a lotof them are worried about the ability of the dot-coms to keeppaying their rent," one Orange County broker tells GlobeSt.com. IfWall Street continues to punish technology stocks, the broker says,"a lot more [high-tech] owners could wind up with a lot of emptyspace."