NEW YORK (TheStreet) -- As per the Institute for Supply Management, the U.S. service sector index rose to 52.6 in December from 52.0 in November after slipping to its two-year low in the previous month. Any reading above 50 indicates expansion in the services sector. Economists expect fourth-quarter U.S. growth to outpace the 1.8% rate recorded in 2011 between July and September, and foresee the economy expanding by a gradual 2% in 2012.

These five stocks have potential upsides ranging from 11% to 44%, with buy and hold guidance of 73% and 22%, respectively, based on average estimates of analysts polled by Bloomberg.

The stocks are listed in ascending order of upside potential.

5. SiriusXM Radio ( SIRI - Get Report) is a U.S.-based satellite radio company. It broadcasts more than 135 satellite radio channels of commercial-free music, as well as premier sports, news, talk, entertainment, traffic, weather and data services to more than 21 million subscribers. SiriusXM offers an array of content from many of the biggest names in entertainment, as well as from professional sports leagues, major colleges, and national news and talk providers.

For the third quarter of fiscal 2011, SIRI reported total revenue of $763 million, up 6% from the 2010 third quarter. Adjusted EBITDA rose 16% to $197 million. Net income increased 54% to $104 million, while free cash flow expanded 22%.

The subscriber base swelled 7% year-over-year to 21.3 million. Net additions in the quarter were 364,004, up 41% from the same quarter the prior year, and the self-pay subscriber base reached an all-time high of 17.5 million, a 7% year-over-year rise. In October 2011, SIRI launched an expanded channel lineup, such as new music, comedy, sports channels as well as Sirius XM Latino -- a suite of Latin channels.

For fiscal year 2012, SIRI anticipates revenue growth of 10%, to more than $3.3 billion, and adjusted EBITDA growth of 20%, to about $860 million.

The company announced last month that it will launch Tiesto's Club Life Radio, the 24/7 commercial-free music channel featuring music by electronic dance music superstar DJ Tiesto.

Of the 12 analysts covering the stock, 75% recommend a buy and 17% suggest a hold. Analysts' average 12-month price target for the stock is $2.28, about 11.6% higher than the current price, according to Bloomberg.

4. MercadoLibre ( MELI - Get Report) is Latin America's leading e-commerce technology company. Through its primary platforms -- and -- it provides solutions to individuals and companies buying, selling, advertising and paying for goods online.

For the 2011 third quarter, the company reported revenue of $81.6 million, up 45.9% from the same period in fiscal 2010. Income from operations grew 55.2% to $30.0 million, whereas gross profit was up 38.4% to $61.6 million.

Gross merchandise volume grew 51.8% year-over-year to $1.348 billion, while total payment volume rose 94.1% year-over-year to $368.5 million.

Credit Suisse ( CS) has initiated coverage on the stock with a neutral rating.

Of the 10 analysts covering the stock, 7 recommend a buy. The stock's average 12-month price target is $99.38, about 23.8% higher than the current price, according to a Bloomberg consensus.

3. ( PCLN) is a leader in global online hotel reservations, with over 200,000 participating hotels worldwide. It operates under four primary brands --,,, Travel Jigsaw -- and several ancillary brands. The company provides online travel services in more than 140 countries in Europe, North America, South America, the Asia-Pacific, the Middle East and Africa.

For the third quarter of 2011, PCLN recorded revenue of $1.5 billion, a 45.0% increase over a year ago. The Group's international operations contributed $953 million, rising 79% from the year-ago period. Gross profit for the quarter stood at $1.1 billion, an increase of 65% from the prior year period, whereas operating income stood at $616.4 million, up 83% from the prior year.

For the 2011 fourth quarter, PCLN expects revenue to grow in the range of 27% to 32% and gross profit to see a 42% to 47% year-over-year increase.

Of the 24 analysts covering the stock, 79% recommend a buy and 17% suggest a hold. The stock's average 12-month price target is $616.24, about 29.4% higher than the current price, a Bloomberg consensus shows.

2. AECOM Technology ( ACM - Get Report) is a global provider of professional technical and management support services to a broad range of markets, including transportation, facilities, environmental, energy, water and government. A Fortune 500 company, AECOM serves clients in approximately 125 countries.

For fiscal 2011, AECOM reported an 22.8% increase in revenue to $8.0 billion. Gross profit for the year stood at $466.7 million, up 8.5%. Net income rose 16.42% to $275.8 million.

Pacific Contingency Services LLC (PCS), a joint venture between AECOM and Shaw Group, was among the six companies awarded the Global Contingency Services contract worth $900 million last month. Furthermore, its wholly owned subsidiary, AECOM Asia Company Limited, has been awarded a consultancy contract of US$148 million, by the Hong Kong Special Administrative Region's Highways Department.

Of the 15 analysts covering the stock, 73% recommend buying and the rest suggest a hold. The stock's average 12-month price target is $28.50, about 34.2% higher than the current price, a Bloomberg consensus shows.

1. Virgin Media ( VMED) is involved in the entertainment and communications business. It is the first provider of all four broadband, TV, mobile phone and home phone services in the U.K. The company delivers ultrafast broadband connections to over half of U.K. homes with speed of up to 100Mb and is expanding this cable.

For the 2011 third quarter, VMED reported total revenue of $1.54 billion, up 2.2% from the same quarter last year. Operating income was $198.2 million, up 26.25%. Gross margin for the quarter improved 2.7%, to $923.57 million.

Mobile contract customers increased 23% to 1.4 million. Cable ARPU grew to $73.9, up 3.2%. The cable customer base expanded 6,300 during the quarter. Churn was up slightly at 1.7%, vs. 1.6% in the third quarter last year.

Last month, the company and BBC announced a new deal that will bring next-generation BBC TV services to the Virgin Media TiVo® Service in 2012, continuing the successful partnership that saw BBC iPlayer launch its first TV platform.

Of the 26 analysts covering the stock, 69% recommend a buy and 19% rate it a hold. The stock's average 12-month price target is $32.17, about 44.8% higher than the current price, a Bloomberg consensus shows.