Centrica (LSE: CNA) is a company undergoing a major transition at the present time, which could lead to significant gains for its investors. For example, it’s selling off a number of assets within the oil and gas space as it seeks to refocus on being a domestic energy supplier in future years. This should lead to a more stable business that has a more reliable income stream.

Clearly, this is good news for the company’s investors, although while the changes are ongoing Centrica is likely to remain relatively volatile. That’s because major change brings a high degree of uncertainty, although with Centrica expected to deliver £750m in cost savings as well as to become a more efficient business, its prospects remain upbeat.

With Centrica currently yielding 5.5%, it remains one of the best yielding stocks in the FTSE 100. And with shareholder payouts due to rise by 2.4% next year, the income from Centrica shares should rise at a faster pace than inflation. Moreover, with Centrica’s dividends being covered 1.3 times by profit, there appears to be adequate headroom to raise real terms dividends over the medium term too.

Income appeal

Also having a high yield and operating within the oil and gas sector is support services company Petrofac (LSE: PFC). Like Centrica, Petrofac is making changes to its business model as it seeks to become increasingly diversified and more efficient in the face of challenging trading conditions. Evidence of them can be seen in Petrofac’s results for 2015, with the company making a loss of $344m due mainly to exceptional items.

Despite this disappointment, Petrofac maintained its dividend in 2015 and it currently yields 4.8%. It expects to return to profitability in 2016. The fact that dividends were maintained indicates that management remains confident in the prospects for the business – especially with revenue rising by 10% last year and Petrofac having a record order backlog of $20.7bn. As such, and while it’s a relatively risky buy, Petrofac continues to be a fairly appealing income stock.

Standout performer

Meanwhile, insurance company Admiral (LSE: ADM) reported upbeat results last week. They showed that it’s making encouraging progress, with pre-tax profit rising by 6% and the company’s departing CEO describing 2015 as an ‘uncut diamond’. And with Admiral yielding 5.5% (including special dividends) and recording a share price rise of 25% in 2015, it was a superb year for its investors too.

Looking ahead, Admiral continues to be well-placed within the car insurance industry due in part to its strong capital position and the fact that it led rivals on price rises last year. Its earnings are due to fall by 2% this year, but then recover to rise by 5% in 2017. And with its shares set to yield 5.3% this year (including special dividends), it remains a highly appealing income play even among what is a relatively high-yielding insurance sector.

Despite this, there's another stock that could be a better buy. In fact it's been named as A Top Income Share From The Motley Fool.

The company in question could make a real impact on your income prospects in 2016 and beyond. And in time, it could help you retire early, pay off your mortgage, or simply enjoy a more abundant lifestyle.

Click here to find out all about it - doing so is completely free and comes without any obligation.

Peter Stephens owns shares of Admiral Group, Centrica, and Petrofac. The Motley Fool UK owns shares of and has recommended Petrofac. The Motley Fool UK has recommended Centrica. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.