The California State Teachers' Retirement System, the third-largest public pension fund in the country, wants to pay someone as much as $230,000 a year, plus a 10% bonus, to be its chief investment officer. That may sound like a pretty enticing opportunity, but only one person answered the ad. That's Thomas Flanigan, who has been in the job at the $65-billion fund since June 1985. Calsters said it will choose an executive search firm shortly to try to attract more candidates. Flanigan, whose current contract expires at the end of the year, wasn't available for comment. The board wants a big pool to choose from, not because it's unhappy with Flanigan, said Emma Zink, the board's chairwoman, but because it feels it should seek the largest number of applicants possible before making a decision by April.