Moss Adams, the largest accounting firm based in the Pacific Northwest, will absorb Silicon Valley’s Mohler, Nixon & Williams at year’s end, the two firms said Wednesday.

Seattle-based Moss Adams ranked 12th among U.S. CPA firms with 2011 net revenue of $323 million, while Campbell, Calif.-based Mohler was 88th with revenue of $34 million, according to the trade publication Inside Public Accounting.

The companies said Mohler’s 25 partners will join Moss Adams, as will almost all of its 135 other personnel. Mohler focuses on the technology industry and also does a lot of employee benefit plan audits, the companies said. It’s the ninth-largest CPA firm based in California, according to Inside Public Accounting.

Moss Adams, which has 22 offices from Bellingham to Kansas City, Kansas, said the addition of Mohler will strengthen its presence in California.

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