LONDON -- We've already looked at three FTSE 100 companies set to go ex-dividend next week, but it's a busy week as payments from firms with years ending in December approach, so here are some more from the top-flight index.

As long as you are holding shares in the following three companies up to April 17, you'll be in the money -- or, if they should fall after that date, you might be able to pick up a bargain.

Tullow Oil (LSE:TLW)
Shareholders in Tullow Oil are set to receive a final dividend of 8 pence per share, taking the total annual payout to 12 pence. That's exactly the same as the previous year and provides a yield of just 1% on the current share price of 1,179 pence. It's perhaps not a great compensation for the firm's share price fall of about 17% over the past 12 months -- but long-term shareholders have done well with Tullow, as the shares are up 16-fold over the past decade.

Smith & Nephew (LSE:SN)
With its full-year results on Feb. 7, Smith & Nephew announced a 50% lift of its final dividend to 16.2 cents per share. Added to the interim payment, it made a total of 26.1 cents per share for the year. On today's price of 752 pence per share, that's a yield of about 2.3%.

The orthopedics, endoscopy, and wound-care specialist is expecting market conditions for 2013 to remain similar to last year's, but we hope to see more of what the company described as "a move to a progressive dividend policy."

Resolution (LSE:RSL)
Resolution is our final pick to go ex-dividend next Wednesday, and again it's a final payment. This time it amounts to 14.09 pence per share, taking the full-year dividend up 6.3% to 21.14 pence and providing an annual yield of 7.9% on the current price of 268 pence. The income will be available only as cash, as the insurance sector restructuring specialist has discontinued its scrip dividend program.

Going forward, the firm will consider a progressive dividend policy once sustainable cash-generation reaches 400 million pounds per year, and it plans to pay one-third of its annual dividend at the interim stage each year.

Dividends like these can add nicely to your investment returns -- they can be spent or reinvested, according to your needs. Whether you're investing for income or growth, good old cash is always welcome. And that's why I recommend the brand-new Fool report "The Motley Fool's Top Income Share For 2013," in which our top analysts identify a share they believe will provide handsome dividend income for years to come. But it will only be available for a limited period, so click here to get your copy today.

Alan Oscroft has no position in any stocks mentioned. The Motley Fool owns shares of Smith & Nephew. 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.