By Lisa Richwine

LOS ANGELES (Reuters) - Netflix Inc's <NFLX.O> disappointing second-quarter subscriber growth and forecast raised questions about whether the streaming video pioneer can pick up the pace of its global expansion, Wall Street analysts said.

At least 20 brokerages cut their Netflix stock price targets by as much as $30 on Tuesday, a day after the company reported it failed to sign up as many new customers as it expected from April to June. Its shares were down 13.7 percent at $85.28 on Nasdaq.

The company, known for shows such as "House of Cards" and "Orange is the New Black," said media reports about price increases of $1 to $2 a month had prompted some customers to cancel their service.

"This suggests the loyalty of Netflix subscribers is thin, which is not helpful for long-term bull arguments," FBR & Co analyst Barton Crockett, who rates the company "market perform," wrote in a note to clients.

"Netflix is making long-term commitments for escalating content costs based on its expectations for (subscriber) growth and pricing leverage," Crockett added.

If the company underestimates both, "it could have trouble hitting aggressive margin expansion targets that are crucial for the equity," he said.

Netflix won over Wall Street with a rapid rise that challenged traditional Hollywood studios, redefined television and fueled "binge watching." It now boasts 83 million streaming subscribers, up from 27 million four years ago.

The company's shares hit a record high of $133.27 in December, but had fallen 26 percent up to Monday's close of $98.81.

As growth in the United States slows, the company is looking for new customers overseas. Netflix has launched in almost every country in the world, at a substantial cost, and now must adapt the service to different markets and cultures as competitors also rush in.

Chief Executive Reed Hastings, on a webcast with analysts on Monday, urged investors to take a long-term perspective. "Internet TV is going to be an enormous market," he said. "We're very confident of that, and our competitive position is very strong."

Some analysts agreed. "Weakness in the stock represents a good long-term buying opportunity given that the full benefits from Netflix's international launch and content investments have yet to be realized," Canaccord Genuity analysts wrote in a client note. Cannacord trimmed its price target to $115 from $120, but maintained a "buy" rating.

JPMorgan analysts said they expected Netflix to work through its pricing changes in the second half of the year and emerge as a bigger and more profitable company into 2017, helped by the price increases.

Netflix's shares trade at about 143 times forward earnings, compared with Facebook Inc's <FB.O> 28 times and Google-parent Alphabet Inc's <GOOGL.O> 20 times, according to Thomson Reuters StarMine.

Only one brokerage, UBS, lowered its recommendation on Netflix's shares, to "neutral" from "buy".

Of 43 analysts covering the company, 24 have a "buy" or higher rating, 14 have a "hold" and five have "sell" or "strong sell".

Netflix said it expected to add 300,000 subscribers in the United States in the current quarter. That's less than half the 774,000 additions expected, on average, by analysts surveyed by FactSet StreetAccount.

The company's estimate that it would sign up 2 million new subscribers in markets outside the United States in the quarter was also well below the average forecast of 2.85 million.

(Reporting by Supantha Mukherjee in Bengaluru; Editing by Ted Kerr and Bernard Orr)