Invesco PowerShares, the fund provider best known for its Nasdaq-100 ETF (NasdaqGM: QQQ), is slashing fees on six of its ETFs—some by as much as 42 percent—in an effort to make the funds more alluring to investors.

Among the ETFs are four funds linked to Rob Arnott’s fundamentals-driven RAFI methodology, including the PowerShares FTSE RAFI Emerging Markets Portfolio (NYSEArca: PXH), which now costs only 0.49 percent, or 42 percent less than it did before at 0.85 percent.

Up to now, PowerShares has not been a part of the ongoing ETF fee war among fund providers that already saw Charles Schwab, Vanguard and, most recently, iShares take measures to increase their ETFs’ competitiveness by lowering expense ratios.

The fee cuts were effective Nov. 21, the company said in a press release on Thursday.

“We believe the lower fees announced today better align the six funds with our existing offerings, and help position the PowerShares family of ETFs for continued growth,” Ben Fulton, managing director of global ETFs for Invesco PowerShares, said in the press release.

The other five affected ETFs, including the three additional RAFI-linked strategies are:

• The PowerShares FTSE RAFI Developed Markets ex-U.S. Portfolio (NYSEArca: PXF) has seen its expense ratio cut by 40 percent to 0.45 percent. The $285.7 million fund previously had an expense ratio of 0.75 percent.

• The PowerShares FTSE RAFI Asia Pacific ex-Japan Portfolio (NYSEArca: PAF) now costs 0.49 percent, some 38.75 percent cheaper than its previous cost of 0.80 percent. PAF has attracted only $62.8 million since it came to market in June 2007.

• The PowerShares FTSE RAFI Developed Markets ex-U.S. Small-Mid Portfolio (NYSEArca: PDN) now costs 0.49 percent, 34.6 percent less than its previous cost of 0.75 percent. The $60 million fund came to market five years ago.

Two of the firm’s 12 factor-driven ETFs were also part of the fee cuts, both linked to S&P indexes. They are:

• The PowerShares S&P International Developed High Quality Portfolio (NYSEArca: IDHQ) is the smallest of all the ETFs included in the price cuts, with less than $20 million in assets. The 5 1/2-year-old IDHQ now costs 0.45 percent, some 42 percent less than it did before at 0.75 percent

• The PowerShares S&P 500 High Quality Portfolio (NYSEArca: SPHQ) also saw its expense ratio cut by 42 percent, to 0.29 percent from 0.50 percent previously. SPHQ is the oldest of the bunch included in this list, having been launched in December 2005, but the fund has attracted little more than $172 million in its seven-year history.

Emerging Markets Funds

The cut on the emerging markets fund PXH gives the fund the upper hand in terms of cost relative to the iShares MSCI Emerging Markets Index Fund (NYSEArca: EEM)—the grandfather of all emerging market ETFs. EEM costs 0.67 percent.

Despite being on the market for nearly five years, the $350 million PXH remains a relatively small player in an emerging market equities segment populated by heavyweights like the $38 billion EEM or even the $56 billion Vanguard MSCI Emerging Market ETF (NYSEArca: VWO), which costs 0.20 percent.

The fee cuts suggest that Arnott, the architect behind the fundamentally focused RAFI index screens, may be having something of a change of heart with regardto pricing.

After all, in an interview with IndexUniverse last summer, Arnott said when it came to fees, the relatively high expense ratios charged for RAFI-linked ETFs were more than justified by the extra return the RAFI methodology often produces.