Perhaps because it was seen coming as far back as last Thursday, news of Halliburton’s (NYSE: HAL) acquisition of rival Baker Hughes (NYSE: BHI) is not doing much to lift beaten up oil services exchange trade funds.

The lack of enthusiasm displayed by the Market Vectors Oil Service ETF (NYSEArca: OIH) and the iShares U.S. Oil Equipment & Services ETF (NYSEArca: IEZ) following news that Halliburton, the world’s second-largest provider of oilfield services, will acquire rival Baker Hughes for $35 billion underscores the sensitivity of these ETFs to oil prices.

On news of Halliburton’s acquisition of Baker Hughes, the second-largest deal in the energy sector this year, OIH is lower by nearly 1% while rival IEZ is off by two-thirds of a percent. OIH, the largest oil services ETF, had a combined weight of nearly 18% to Halliburton and Baker Hughes as of last Friday’s close. IEZ devoted almost 17% of its combined weight to those stocks heading into today.

The two ETFs are trading lower Monday partly because oil prices are down again. West Texas Intermediate futures are struggling to stay above $75 per barrel and even though prices are at four-year lows, OPEC members are resisting calls to pare production.

It might come as a surprise to some, but as the chart below depicts, the one-year correlations of OIH, IEZ and the SPDR Oil & Gas Equipment & Services ETF (NYSEArca: XES) to the United States Oil Fund (NYSEArca: USO) and the United States Brent Oil Fund (NYSEArca: BNO) are not overly intimate.

Chart Courtesy: State Street

Still, there is no denying falling oil prices are problematic for oil services stocks and ETFs. Over the past three months, IEZ and OIH are down an average of more than 18%. USO is lower by 18.6% over the same period. Over that time, only 23 ETFs have lagged OIH. Highlighting the lingering weakness in the energy patch, 10 of those 23 ETFs are energy-related. [Maybe Some Help for Oil Services ETFs]

That says more M&A news needs to be coupled with rebounding oil prices to earnestly lift OIH and IEZ. The M&A scenario could come to pass as National Oilwell Varco (NYSE: NOV), the third-largest holding in both OIH and IEZ, is seen as a potential target.

Based on last Friday’s close, Halliburton is offering $80.69 per share for Baker Hughes, a roughly 34% premium to where the latter’s shares closed. A 34% premium for National Oilwell Varco would value the company at over $41 billion based on the company’s current market value of just under $30.9 billion.

Several of OIH’s smaller components, including Nabors Industries (NYSE: NBR), Rowan (NYSE: RDC), Dresser Rand (NYSE: DRC) and Weatherford International (NYSE: WFT) have been previously mentioned as takeover targets.

Market Vectors Oil Service ETF