Vanguard, the third-largest U.S. issuer of exchange traded funds, announced Thursday it has lowered the annual expense ratios on nine of its ETFs, including the Vanguard Total Bond Market ETF (NYSEArca: BND).

BND, one of the largest U.S. bond ETFs, now has an expense ratio of 0.08%, down from 0.1%. Vanguard made the announcement Tuesday, but Securities and Exchange Commission filings updated earlier this month reflect modest fee reductions made on April 7 and April 17.

On April 7, the Vanguard FTSE Developed Markets ETF (NYSEArca: VEA) began trading with annual fees of 0.09%, down from 0.1%.

As of April 28, the Vanguard Value ETF (NYSEArca: VTV), Vanguard Growth ETF (NYSEArca: VUG), Vanguard Small-Cap ETF (NYSEArca: VB) and several other Vanguard ETFs saw their expenses drop to 0.09% per year from 0.10%.

“Vanguard has long been a low-cost leader, which can be attributed to our unique corporate ownership structure and our relentless pursuit to operate more efficiently and productively. Vanguard is owned by our funds—and, in turn, collectively owned by the fund shareholders. We provide services at cost, returning any “profits” to fund investors in the form of lower expense ratios. It’s a structure that enables us to pass along economies of scale—and reduce expenses—as fund assets grow,” said the issuer in a statement.

In February, Vanguard reduced fees on five of its international ETFs, including Vanguard FTSE Emerging Markets ETF (NYSEArca: VWO), the largest emerging markets ETF by assets. In April 2013, the Pennsylvania-based company pared expenses on seven ETFs, including three bond funds. [Vanguard Lowers Fees on Five Global ETFs]