BOSTON (AP) — Vanguard Group is trying to bolster its appeal to cost-conscious investors by reducing a key expense of investing in low-cost index mutual funds: fees paid to firms that license benchmarks covering segments of the stock market that the funds track.

The nation’s largest fund company said on Tuesday that it has negotiated lower-cost index licensing deals that will result in 22 of its index funds switching to new benchmarks, and adjusting the stocks they invest in accordingly.