The number of exchange-traded funds has surged the past few years, bringing a unique business opportunity to Russell Indexes in Tacoma.

The division of Russell Investments began licensing its indexes 10 years ago to large and small ETF providers as a way of developing another revenue stream.

Though Rolf Agather, Russell's director of index research and innovation, would not specify how much Russell has generated from this initiative, he said it is seeing a "growing portion of revenue" coming from licensing.

"For a lot of people, it is about having a recognizable brand," he said. "People want to invest in a fund that is backed by an index with an accurate and broad representation, but obviously having a name like Russell creates a certain affinity."

Agather said he thinks Russell offers more substance than, say, a pair of Nike sneakers, but will not deny that, like with Nike, simple brand recognition helps.

"We have been doing this for 25 years," he said. "We have evolved the methodology and developed these indexes. There are advantages to investing with a known index."

Currently, $4 trillion is benchmarked to Russell's family of global equity indexes and $65 billion is managed against these indexes in the form of exchange-traded funds. Sixty-three ETFs, from providers including ProShares and Rydex, use Russell's indexes. A year ago, 55 ETFs with $53.2 billion of assets under management benchmarked to Russell's indexes.

Last week, Vanguard Group announced plans to add 19 new funds by the end of this year, including ETFs based on the large-cap Russell 1000 index and the small-cap Russell 2000 index.

A broad market fund and ETF that would track the Russell 3000 index would also be introduced.

Melissa Nassar, a principal at Vanguard, said the company is interested in offering best-in-class products to its clients.

"Now that best practices have become much more mainstream, we can bring to market a wider array of products from different index providers and allow investors who want to invest in ETFs to benefit from our value proposition: low-cost, product expertise from brand names they can trust," Nassar said.

Analysts said other large index providers, including Standard & Poor's and MSCI, are also licensing to ETF providers.

"There are just a finite number of indexes and a growing pool of firms that want to offer ETFs," said Burton Greenwald of BJ Greenwald Associates. "Initially, indexes were used exclusively, but as this industry has grown, so has the opportunity for licensing."

Agather said that there is still a "first-mover advantage" in ETFs. He said companies that launch against an index first are typically the most successful, but "because Russell indexes are used in such different ways there is room for additional providers."

Russell has more opportunities in its pipeline, Agather said. The company is creating new indexes, including a factor index that was launched earlier this year, and hopes to continue to license its indexes to ETF providers, he said.

Ruthie Ackerman contributed to this story