LONDON -- Ex-dividend dates are well worth watching out for, whether or not you own shares in a company. It's important if you want to be eligible for a dividend payment, and so long as you hold the shares up to and including that day, you'll get your money. It can also be a good time if you're looking to buy on potentially overdone share price falls.

We have more FTSE 100 companies reaching their ex-dividend dates next week. Here are three that will go ex-dividend next Wednesday, May 22.

HSBC (HSBA -0.61%) (HSBC -0.86%)
On May 7, HSBC Holdings announced a first-quarter dividend of $0.10 per share. As has been the company's policy since its last annual report, it will pay an equal dividend for each of the first three quarters, with the final dividend being variable. The latest City forecasts suggest a full-year payout of about 33 pence per share, which would be about 14% up on last year.

With HSBC's share price having risen by about 35% over the past 12 months to 754 pence, a 33 pence annual dividend would amount to a yield of 4.4%, and that's the biggest among the FTSE 100 banks.

Intertek (ITRK -0.80%)
Intertek Group, the quality and safety services group, has proposed a final dividend of 28 pence per share, making a total for the year of 41 pence when added to a first-half payment of 13 pence. That's a rise of 22% over the previous year, providing a yield of 1.2% on the current share price of 3,457 pence.

The rise in the annual payout was made possible by 19% growth in pre-tax profit to 308 million pounds, with diluted earnings per share up 25% to 106.7 pence. And though the actual dividend payment is modest, Intertek shareholders have also benefited from a rise in their share price of nearly 40% over the past 12 months.

Carnival (CCL 1.17%)
Cruise operator Carnival announced a first-quarter dividend of $0.25 per share on April 17 after reporting flat earnings for the three months to February -- unchanged from last year's Q1 payment. The firm turned a $141 million pre-tax loss for the same quarter the previous year into a $37 million profit, which is pretty good progress for such a quiet quarter.

Forecasts for the year to November 2013 suggest a total dividend of about 69 pence per share, which would provide shareholders with a yield of 2.9% on the latest share price of 2,399 pence. If those expectations hold out, that will be a rise in the full-year dividend of about 8.5% over last year, and for 2014 there's a further 10% or so predicted.

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