Similar funds already exist but BlackRock's iShares MSCI Frontier 100 Index Fund may be the first to offer a truly global portfolio, according to one analyst.

The iShares fund invests in frontier market securities that are screened for liquidity and tracks the MSCI Frontier Markets 100 Index, according to a company statement issued on Thursday. Currently the index includes markets such as Croatia, Argentina, Nigeria, Vietnam and the United Arab Emirates.

There are only four other frontier markets ETFs available in the United States. The $17 million PowerShares MENA Frontier Countries ETF , the $13 million WisdomTree Middle East Dividend ETF and the $11 million Market Vectors Gulf States ETF , are limited to investing in the Middle East and Africa, according to IndexUniverse LLC.

The fourth ETF, the $142 million Guggenheim Frontier Markets ETF , has much broader exposure with some overlap into emerging markets. The vast majority of its exposure is Chile, Columbia and Peru, according to the firm. The fund tracks the BNY Mellon New Frontier DR Index.

"You aren't getting a lot of frontier with your frontier fund with FRN," said Dave Nadig, director of research at IndexUniverse.

With its new frontier markets ETF, iShares is providing investors with the ability to invest in the first "real global frontier ETF," Nadig said.

This could be particularly attractive for investors who are looking to invest beyond emerging markets because as more emerging markets companies have begun expanding internationally, they have started to perform more like developed markets, he said.

The iShares ETF costs a bit more than its peers at 0.79 percent, compared to the Guggenheim ETF, which costs 0.70 percent.

The new ETF may be particularly attractive to managers overseeing model ETF portfolios, a growing market in the ETF space which BlackRock is targeting [ID:nL2E8I9368].

BlackRock projects the ETF model portfolio market, now at around $46 billion, will climb to $120 billion by 2016.

"If you are a manager running a model portfolio, you want these kinds of ETFs as building blocks that are different from the rest of your portfolio," he said.

(Reporting By Jessica Toonkel; editing by Andrew Hay)

By Jessica Toonkel