LONDON -- In this festive mini-series, we look at the 2013 prospects for some of your favorite FTSE 100 (UKX) shares. Today, it's the turn of BG Group (LSE:BG) (NASDAQOTH:BRGYY).

BG was once the can-do-no-wrong darling of the U.K. oil and gas sector. But that image has been tarnished somewhat in 2012 -- a year that's seen BG's shares fall 24% compared with an average 8% fall for the sector and a 6% gain for the FTSE 100.

The year began swimmingly enough for BG, its shares rising 10% to over £15 before the end of March. The stock suffered during the general market correction in the summer, but the real damage to the year's performance came at the end of October when the company released its Q3 results. The shares fell 14% on the day and were trading as low as £10 by mid-November.

What didn't the market like about BG's Q3 statement? The big shock was that the company said it expected zero production growth in 2013. This was not only below market expectations for the year, but also seemed to put a dent in the company's longer-term target of compound annual growth of 6%-8% through to 2020. The market, evidently, was not interested in the fact that much of the production would merely be deferred rather than lost.

Earlier this month, BG announced that Chris Finlayson would succeed Sir Frank Chapman as the group's chief executive from January 1. The Footsie has seen plenty of new CEO appointments in the last few years, many at companies that have been in a crisis of one kind or another -- and such appointments have led to the inevitable strategic review and subsequent restructurings as the new CEO imposes his view of the best way to move the business forward.

Despite BG's hiccup in production, it can hardly be described as anything like a company in crisis. Chapman's intention to retire was announced as long ago as 2011, so the appointment of Finlayson simply constitutes an orderly succession. I don't expect the new CEO to make any fundamental changes to the company's present strategy. That strategy is to divest non-core assets to raise capital toward funding the commercialisation of the group's largest and most valuable resources, most notably in Brazil's offshore Santos Basin.

The fall in BG's share price puts it on a discount to its asset value -- true asset value, rather than book value -- which some analysts calculate to be as much as 30%-40%. However, if the market's ignoring the asset valuation in rating the shares now, there seems little reason to suppose it won't go on ignoring it in 2013; and, instead, wait for visibility on production growth prospects for 2014.

There is, though, something that could drive BG's shares up. While stock market investors seem to be dismissing the value of the company's assets, corporate executives and mergers and acquisitions advisors might just be rubbing their hands about the discount. BG has been the subject of takeover speculation in the past, and a bid -- or even a rumour of one -- would certainly see BG's shares at a higher level during 2013 than they are going into the year.

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G. A. Chester has no positions in the stocks mentioned above. The Motley Fool has no positions in the stocks mentioned above. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.