Santa Rosa City Schools Superintendent Sharon Liddell announced Friday she will resign effective June 30.

Liddell, who turns 65 next month, has been with Sonoma County's largest school district since 2003. She became superintendent in 2005.

"This is something I have been thinking about for a number of months," she said. "I have some goals I'd like to achieve."

Liddell said she has been in contact with employment search firms and is considering moving to a larger school district or possibly teaching at a university.

The seven members of the school board were notified of Liddell's decision Feb. 8. District administrators were told Thursday and a letter was distributed to all staff members Friday afternoon.

"So far, just walking down the hall and hearing people talk about it, there is genuine surprise," said Andy Brennan, president of the Santa Rosa Teachers Association and a teacher at Santa Rosa High School.

Although students across the district have made academic gains since 2005, they have not been enough to keep the district out of three consecutive years of federal sanctions under the No Child Left Behind law.

Liddell's tenure also has been marked by dramatic budget cuts, but board vice president Bill Carle said other districts have faltered under similar conditions.

"There are other districts that imploded, that found reasons to infight," he said.

Santa Rosa City Schools did not, he said.

"We've had the vast majority of our team pulling in the same direction for many years," he said. "I think we were really lucky to have Sharon to be able to do that."

Liddell leaves the district in a time of financial uncertainty and as officials ponder turning to voters to support a tax that would offset some of the deep cuts in state spending in recent years.

The 15,500-student district has cut $24 million from the budget since 2008-09. The district has cut school days from the calendar, eliminated librarian positions, increased class sizes, eliminated adult education, reduced maintenance spending and on Wednesday will consider closing Doyle Park Elementary School.

The district is preparing to cut $8.3 million from the proposed $130 million budget for the 2012-13 school year.

"She took charge at a very difficult time with budget cuts and Program Improvement and she did the best she possibly could in rough circumstances," said Brennan, the teachers' association president. "They made some very difficult choices and it's hard to second guess whether things could have been done better."

Tammy Affonso, president of California School Employees Association Chapter 75, called Liddell an "excellent leader."

"There is probably no good time for it to happen, but during this time I think it's going to add a little unrest to the district," she said. "We have had a wonderful working relationship with her."

Board member Laura Gonzalez said she was "surprised and disappointed" by the announcement. She credited Liddell with being transparent in district business and fostering communication with board members and the community.

"I don't always agree with her and her decisions, but to me that is not the important part," she said. "I trust her. So for me that is much more important than we always agree."

In the coming weeks, board members are expected to decide whether or not to commission a voter survey to gauge support for a tax measure. Liddell's impending departure should not affect how voters feel about a tax, Carle said.

"It's not built on any one person," he said.

Brennan agreed. "I don't think it will have an impact," he said.

Liddell has announced her resignation once before.

In February 2008, she announced she would leave Santa Rosa City Schools, saying financial issues related to her 2005 divorce were forcing her to move out of state.

The school board subsequently voted in April to give Liddell a $25,000 incentive payment to stay. At the time Liddell said she would give the money to her ex-husband in exchange for a cap on his interest in her retirement income. Five days later, after fervent community uproar, Liddell said she would not take the payment.

On Friday, Liddell said that situation has been put to rest. "It's not an issue anymore," she said. "It's been resolved through the state of California and through (California State Teachers' Retirement System)."

She said she does not plan to take extended periods of time off prior to her last day June 30.

"I'll take some time off and on to go do some exploring," she said. "I have no extended vacation plans."