In a move that blindsided Alameda officials by its suddenness, City Attorney Teresa Highsmith is expected to take over today as interim city attorney for the city of Barstow.

The announcement that Highsmith was apparently leaving came Monday night during the City Council meeting in Barstow, where she told local officials that she was looking forward to beginning the new job.

Yvette Abich-Garcia, the outgoing city attorney for Barstow, said Highsmith would take over the position effective Dec. 24.

As of Wednesday afternoon, however, Highsmith had not resigned from her Island post. Her contract requires her to provide at least a 60-day written notice if she plans to quit or retire.

"It's an honor to be asked to be your interim city attorney," Highsmith told Barstow officials from a seat on the dais during the meeting Monday night. "I'm looking forward to getting to know you very well and I hope that I can step into the shoes of Yvette Abich-Garcia, who has served you so well."

Alameda city officials declined to comment Wednesday on Highsmith's apparent departure, saying it would not be appropriate since she still not had officially resigned.

But officials said privately that her decision caught them especially off-guard because they learned about it only after Highsmith had addressed the council in Barstow.

Highsmith could not be reached for comment.

"At this point, she has not informed the council," said Beverly Johnson, the former Alameda mayor who was sworn in as a council member Tuesday night. "She also has not resigned from her job with the city of Alameda."

The City Council in Barstow selected Highsmith as interim city attorney during a closed session Monday night. She is expected to remain in the post until a permanent attorney is hired.

Highsmith will work for Barstow under a contract the city has with Colantuono & Levin, the law firm that Alameda officials secured earlier this year to investigate Councilwoman Lena Tam over allegations that she leaked confidential city e-mails to SunCal Companies during talks on the future of Alameda Point.

Barstow's outgoing attorney, Abich-Garcia, also works for the law firm.

Highsmith replaced Carol Korade as Alameda city attorney six years ago. Before taking over the job, she served as Korade's assistant for nine years.

Her Alameda contract will expire in June 2012 and guarantees her a base salary of $182,000 annually.

Any temporary replacement for Highsmith would be the latest top Alameda official to serve on an interim basis.

Currently Mike Noonan is interim Alameda police chief after Walt Tibbet took over as police chief in Fairfield, and Mike Fisher is interim fire chief after Dave Kapler quit amid allegations that he inappropriately used city gas to fuel his personal vehicle.

Anne Marie Gallant has been serving as interim city manager after Debra Kurita quit the job in February 2009 over what she described as differences with the City Council.

Alameda officials also may need to hire an interim economic development director next month, when Leslie Little will leave the position to become assistant city manager in Morgan Hill.