Sunday share tips: Tullow Oil, AstraZeneca, Aviva

It may be time for Aidan Heavey to step aside at Tullow Oil. The former accountant, 59, is rightly feted as one of the oil industry's great entrepreneurs. Beginning with a tiny start-up in 1986 the Irishman turned Tullow into one of the most successful explorers in the world. Its 10.7bn pound market value makes it the fourth largest London-listed oil company, after BP, Shell and BG Group. But Tullow has become a victim of its own success, and it is not clear if Heavey is the best man to transform it from a finder of new oil fields to a developer of them.Heavey this month sought to reassure the market that Tullow was the same intrepid explorer investors had come to love. He pledged to drill 40 exploration wells this year ? roughly double the amount BP has lined up. But the truth is that Tullow is not the same. It has more balls in the air than ever. The company and Heavey are seen as one and the same, and that has served it well. But any serious wobbles and opinions can change quickly. Just ask Frank Chapman, The Sunday Times´s Danny Fortson says.There is good news for investors in the Midas Dogs of the Footsie portfolio. The shares are behaving as they should, rising in price and delivering generous yields as well. Out of the ten stocks in their experimental portfolio, eight have risen in price over the past quarter and the other two have fallen only slightly. The portfolio consists of the top ten highest-yielding stocks in the FTSE 100. Last October, these were insurers Admiral Group, Standard Life, Aviva, RSA and Resolution; utilities National Grid, SSE, and Vodafone; defence group BAE Systems and drugs giant AstraZeneca. Insurers moved ahead across the board late last year as sentiment towards the Eurozone improved and stock markets recovered. The insurance Dogs were no exception, particularly Resolution, which has risen 23 per cent to 266p since October. It had long been criticised for its complex corporate structure, but it has pledged to simplify the way it operates. Even after the recent gains, it was still their top Dog with a yield of almost 7.9%. The Footsie has risen 9.6%, so £10,000 would be worth £10,707. The Dogs are almost there on share price alone, but investors have also reaped those dividends. Let's hope the Dogs retain their momentum in the next quarter, the Financial Mail on Sunday´s Midas column writes. Drugs giant AstraZeneca will issue its 2012 results on Thursday, which are expected to show a slump in revenues and profit because of patent expiries. However, investors will be very keen to hear what Pascal Soriot, Astra's new chief executive, says about the company's future strategy. There will not be a detailed point-by-point presentation of a definitive strategy. This is expected at a capital markets day, which is likely to happen in March. However, no major strategic shift is expected and Astra is unlikely to go down the GlaxoSmithKline route of branching out into consumer products. Innovation and scientific research will remain at its core. Current consensus forecasts expect profits to fall by a third this year. Indeed, there is a great deal of caution in the analyst community over Astra's prospects, with almost three times as many analysts recommending investors sell the shares than buy. There are 17 analysts saying sell and 6 recommending a buy, according to Bloomberg data, with 17 others saying hold. The average price target is £29.41, below the current share price. However, this hasn't stopped the shares from rallying ahead of the statement to highs not seen since mid-2011. The shares are trading on an earnings multiple of 8 and investors should hold on to the shares ahead of the update, The Sunday Telegraph´s Questor team believes.Please note: Digital Look provides a round-up of news, tips and information that is impacting share prices and the market. Digital Look cannot take any responsibility for information provided by third parties. This is for your general information only as not intended to be relied upon by users in making an investment decision or any other decision. Please obtain a copy of the relevant publication and carry out your own research before considering acting on any of this information.