Collette Chilton, CIO of Lucent Asset Management, which manages the $34 billion pension fund of Lucent Technologies Inc., is leaving the firm to become the first CIO of Williams College's $1.5 billion endowment. Ms. Chilton's last day at Lucent will be Sept. 8, Lucent spokeswoman Joan Campion said. No announcement has been made about Ms. Chilton's replacement, and Ms. Campion refused to provide details about how the position will be filled. Ms. Chilton will start at Williams College, Williamstown, Mass., in October, said Jim Kolesar, college spokesman. The endowment has been managed voluntarily by the finance committee of the college board of trustees, but "that model became unsustainable," Mr. Kolesar said. Ms. Chilton will be based in Boston.