LONDON -- Professional investment analysts have great access to data and management. The level of insight they possess is far ahead of what most armchair investors can manage. So when they rush to upgrade profit forecasts, there are normally good reasons.

Here are the 10 largest companies that have been upgraded at least five times in the last month:

Company

Price (pence)

Upgrades in Last Month

P/E (forecast)

Yield (forecast)

Market Cap (millions of pounds)

Royal Dutch Shell (LSE: RDSB.L)

2,194

5

8.2

5.1%

82,015

BG

1,322

7

15.5

1.2%

44,949

Diageo

1,781

5

17.2

2.7%

44,677

Barclays

236

6

7.1

2.7%

28,909

Imperial Tobacco

2,299

5

11.5

4.5%

22,742

Royal Bank of Scotland (LSE: RBS.L)

268

7

13.4

0%

16,722

Fresnillo (LSE: FRES.L)

1,927

6

29.6

1.8%

13,823

Antofagasta

1,264

7

14.7

2.4%

12,465

British Sky Broadcasting (LSE: BSY.L)

750

7

13.4

3.8%

12,407

Wolseley

2,660

6

14.7

2.6%

7,616

Source: Stockopedia.

These four looked particularly interesting.

1. Royal Bank of Scotland
RBS is the share that investors have been writing off for years. Apparently the company was facing irresistible headwinds. Today, though, attitudes toward RBS are showing signs of thawing.

Shares in RBS are up 35% in the last three months. For 2012, analysts are forecasting earnings per share of 20.0 pence, which is expected to increase to 27.5 pence for 2013. While there is still no dividend, the expectations are that RBS will start paying again for 2013. This would be a significant milestone in RBS's rehabilitation.

So why have analysts been upgrading their expectations?

Nic Clarke is a banking analyst at City stockbroker Charles Stanley. He explains the upturn thus:

RBS has made good progress de-risking its balance sheet. RBS has improved its capital ratios and loan-to-deposit ratio. RBS is now in the last stages of running down its non-core bank and has exited the expensive Asset Protection Scheme. Combined with better news from the U.K. economy and EU policymakers, the result has been an improvement in investor sentiment.

2. British Sky Broadcasting
Today, Sky is more than just a pay-TV company. Sky's triple-play offering of TV, telephone, and Internet is enjoying increased penetration of the U.K. market. Sky continues to recruit more customers and sell them more services.

In its most recent annual results, the company reported its customer base increasing 3%. The value of these customers was accelerated by a 21% increase in subscribers paying for all of Sky's three main services.

Sky continues to innovate and deliver more content and products into the market. In particular, Sky Go is the company's service to subscribers that want to watch programs on a tablet or smartphone. Possibly more exciting, however, is the development of NOW TV. This is a parallel service to Sky that is out to compete with LoveFilm and Netflix.

Analysts expect EPS growth of around 4% this year and next. Dividend growth is expected to be slightly higher.

3. Fresnillo
Fresnillo is a leading precious-metals explorer. The company's assets include the world's largest silver mine, after which the company is named.

As you may have expected, the precious-metals boom has enriched Fresnillo shareholders. In the last five years, the shares are up almost threefold.

Recent production figures from the company impressed the market. Fresnillo reported record gold production in the year to date. The company also assured the market that its own production targets for the full year would be met.

Resources companies such as Fresnillo are a geared play on the price of the commodities they produce. As such, an improved outlook for mineral and metal prices will often result in earnings upgrades for miners. Policy developments in the U.S. and the eurozone have provided some support for precious-metal prices. In the last three months, the price of silver has increased 27%, while gold is up 9%.

The benefit to Fresnillo investors is clear: The shares have advanced 36% in the last three months.

4. Royal Dutch Shell
Next year's profit forecasts for Shell have risen steadily since August. The consensus of opinions currently puts the shares on a 2013 P/E of just 7.7. The expected yield for 2013 equates to 5.3%.

These ratings are significant. Rarely in the last five years has this FTSE 100 titan been so cheap on both earnings and dividend measures. Of course, that doesn't mean that the shares cannot get cheaper; in June, Shell was priced at around 2,000 pence.

As fears for the global economy have eased, the price of oil has been increasing. In the last three months, crude-oil futures are up 10%. At a company like Shell, this obviously feeds through to analysts' profit expectations.

Today, the analyst consensus is for Shell to deliver $4.32 per share in earnings in 2012. While this is down from 2011, it is significantly more than what the company made in 2009 and 2010.

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