As more investment pros warn of a bubble in Treasuries, State Street Global Advisors is launching an intermediate-term bond exchange-traded fund focused on investment-grade corporates and government debt.

The SPDR Barclays Capital Intermediate Term Credit Bond ETF (NYSEArca: ITR) started trading on Wednesday. It's expected to come with an annual expense ratio of 0.15%. It will follow an index of more than 2,500 bonds and a weighted maturity of 5.2 years. 

While ITR enters an investment-grade intermediate bond field with a few established competitors, the new ETF does track an index that offers somewhat different investment features than its rivals.

Although it can invest in agency and related noncorporate securities, ITR's holdings at least initially are heavily slanted toward investment-grade corporate bonds. Two sectors, Industrials (37.4%) and Financials (36.2%), dominated constituents of the ETF's underlying index. Agencies and local authorities made up a combined 8.6%. 

"With current yield spreads edging wider than they have been in more than 15 years, investment-grade corporate bonds are an attractive asset class for investors seeking to diversify their fixed-income holdings or hedge against future interest-rate hikes," said James Ross, senior managing director at SSgA, in a statement.

The new ETF also has a sprinkling of some sovereign debt. It might be interesting to note that an established competitor is the iShares Barclays Intermediate Credit Bond ETF (NYSE: CIU). It has some 16.71% of noncorporate investment-grade issues and follows almost the exact same index as ITR.

However, the Barclays credit benchmark used by CIU is strictly U.S. bonds. And the iShares intermediate bond ETF charges a slightly higher expense ratio of 0.20%. 

Vanguard also has an ETF competing in this area. Its Intermediate-Term Bond ETF (NYSE: BIV) tracks another highly diversified Lehman benchmark made up of high-grade corporates, government and international bonds. It holds about 7% in foreign issues and more than 50% in U.S. Treasuries and agencies. Most of the rest, 40%-plus, is in corporates.  

Besides charging 0.11% in annual expenses, BIV has a slightly higher average duration for its portfolio.