(Reuters) - A rapid rise in the dollar has hurt second-quarter financial results and some U.S. companies are warning that the pressure could persist in future quarters.

The U.S. dollar has risen 2.5 percent so far this year .DXY against a basket major currencies with most of its gains coming in the second quarter. As a result companies are starting to reevaluate their currency hedging strategies.

Here are some of the U.S. companies blaming the stronger greenback for weaker revenue or profits:

* Netflix Inc NFLX.O said last week that current-quarter operating profit margins would be narrower than previously expected because of strength in the U.S. dollar. Most of Netflix' growth comes from overseas, but the majority of its costs remain dollar-denominated.

* Illinois Tool Works Inc ITW.N saw its shares tumble Monday after it slashed its full-year outlook, citing the strong dollar. It forecast a 12-cent per share negative currency impact compared with its previous forecast for the second half of the year and set 2018 full-year EPS guidance in a range of $7.50 to $7.70 per share, down from its previous target range of $7.60 to $7.80 per share, issued in April

* Kimberly-Clark Corp KMB.N lowered its full-year 2018 forecast for adjusted earnings per share to a range of $6.60 to $6.80 from a previous $6.90 to $7.20, citing a stronger dollar along with higher commodity prices.

* EBay Inc EBAY.O said on July 18 it expects the strong dollar to hit revenue by $150 million for the full year, and it cut its full-year revenue forecast to a range of $10.75 billion to $10.85 billion, from $10.9 billion to $11.1 billion.

* Omnicom Group Inc OMC.N, already hurt by shifts in spending by U.S. clients, warned on July 17 that the strong dollar would hurt revenue by 1 percent in the third and fourth quarters this year.

* Oracle Corp ORCL.N said on June 19 it expects exchange rates to shave 1 percent off its current-quarter revenue.

* Cruise operator Carnival Corp CCL.N said on June 25 that exchange rates and fuel price increases would eat into 2018 adjusted earnings per share, currently expected to be in the range of $4.15 to $4.25.

* Akamai Technologies Inc AKAM.O on June 26 cited a stronger U.S. dollar when it cut the upper end of its target range for second-quarter adjusted profit and revenue. The company, due to report results on July 31, said it expects adjusted profit of between 79 cents and 81 cents per share, cutting the high end of the range from 83 cents per share. It now expects revenue between $658 million and $663 million, cutting the high-end of the range from $670 million.