WTAS, the US tax advisory firm, has appointed three managers to the role of director within its San Francisco office.

The promotions include Stephen deHaan and Mamie Chew - who are both members of the firm's private client services practice - and Kelly Ackel, who is a member of the firm's valuation team.

DeHaan's experience involves implementing estate, gift and income tax strategies for ultra-high net worth family groups and individuals, executives at early-stage companies and closely-held businesses, the firm said in a statement.

Chew works primarily with HNW family groups and individuals, with a specialization in pre-divorce forensic accounting, domestic couples, stock option planning for individuals at start-ups, agribusiness and estate planning.

Ackel is an accredited senior appraiser in business valuation, with experience in valuation of closely-held businesses, business interests, intangible assets, intellectual property, debt instruments and derivatives.

The appointments account for three of eight promotions to director across the firm's 14 offices, WTAS said.

In related news, the firm made a raft of promotions at its private client services, estate planning and alternative investment fund practices earlier this year, including that of Michael Hough to managing director in the private client services group in Boston, and Joseph Kluemper, Carl Fiore and Janet Peng in New York.