One in five American pay-TV subscribers may cancel service in the next few years, primarily because they find multichannel video services too expensive, according to a new survey by Credit Suisse.

Overall, 25% of consumers surveyed by the firm currently subscribe to or use an over-the-top service, such as Netflix, Hulu Plus or Amazon Prime Instant Videos. Roughly half of those said they use these services as a substitute for pay TV, with the other half indicating that Internet-delivered video services are complementary to cable, satellite or telco TV, Credit Suisse found.

Among those who don't subscribe to pay-TV, 50% said the reason was the high cost of multichannel video services -- the single biggest factor cited. Other reasons non-pay TV users cited were that they "don't watch a lot of TV" (22%), "just watch broadcast TV over the air" (16%) and "don't find pay TV channels compelling" (14%).

The survey shows the fundamental issue for pay-TV "is the declining value proposition for a portion of the customer base, not OTT services, in and of themselves," Credit Suisse analysts Spencer Wang and Shub Mukherjee wrote in a report issued Thursday.

Roughly 4% of current subscribers say they plan to drop service in the next 12 months, according to the survey.

The findings were based on a survey of 2,075 consumers conducted in August 2011. Credit Suisse fielded the survey as a follow up to its study in September 2010, which found that 17% of Netflix users already have dropped pay-TV service; as a result, the analysts downgraded their rating on the U.S. media sector.

In last month's survey, 80% of pay-TV subscribers cited sports, live TV and/or choice as reasons for subscribing to cable, "implying that this segment is unlikely to cut the cord for the foreseeable future," the analysts wrote. However, that also indicates that the remaining 20% are susceptible to dropping service.

The survey also found that 4% of subscribers to premium networks such as HBO, Showtime and Starz are considering canceling in the next 12 months.

When Credit Suisse asked respondents if they would be interested in an à la carte over-the-top offering from the likes of HBO (i.e., unbundled from a cable TV subscription) 20% agreed -- however, the premium programmers have resisted going direct-to-consumer because they would anger their existing pay-TV affiliates.

Credit Suisse cautioned that its survey population underindexed on pay TV penetration at 68% compared with 87% for the U.S. according to industry estimates. The firm attributed the disparity partially to a relatively large portion of respondents who indicated that they have no TV or watch only broadcast TV.

The analysts maintain their "underweight" rating on the U.S. entertainment sector. For investors looking to "play growth in OTT services," Credit Suisse highlighted Netflix and Google -- both rated "outperform" -- and Amazon.com, rated neutral.