D.A. Davidson has formally completed a deal announced in May to merge with fellow West coast regional brokerage Crowell Weedon.

The combination adds significant scale to D.A. Davidson’s advisory operations, which now increase from 310 financial advisors to around 460. Combined assets under management now total approximately $43.5 billion. Both firms are privately held and did not disclose the price of the transaction.

“Mergers are always best when one and one is a little bit more than two, hopefully significantly more than two,” said  Bill Johnstone, the chairman and CEO of D.A. Davidson, in an interview. “I talked about it as a combination, bringing the best practices, skills and values of each organization together, and we’ve consistently stayed true to that as we worked our way through the negotiation and integration.”

Johnstone said that the deal will also open up opportunities for Great Falls, Mont.-based D.A. Davidson to build up its presence in Southern California and Crowell Weedon’s headquarter city of Los Angeles. Crowell Weedon, which retains its name at least initially during the operational integration, will become D.A. Davidson’s fifth regional hub in Los Angeles in addition to Great Falls, Denver, Portland, and Seattle. Andrew Crowell, the former president and CEO of Crowell Weedon, will become the president and regional head of the Los Angeles hub.

Both firms had a similar regional culture and would benefit from the increase in product offerings, services and resources, Johnstone added.

“We’re not only interested in scale, but scale is important in this business in order to leverage some of the significant fixed costs: compliance, technology, products and service support,” Johnstone said.