An array of companies, including Wal-Mart will issue special dividends next month or move dividend payouts earlier. (Bill O'Leary/WASHINGTON POST)

For shareholders of companies trying to get ahead of tax hikes at the end of the year, this December will include an especially big Christmas gift.

An array of companies, from Las Vegas Sands to Wal-Mart, will issue special dividends next month or move dividend payouts earlier in order to get ahead of Jan. 1, when the top tax rate on dividends is set to more than double, from 15 percent to 43.4 percent.

The year-end rush is the latest sign from companies that they’re making plans to avoid the “fiscal cliff,” when George W. Bush-era tax cuts are set to expire.

Democrats and Republicans could still hammer out a deal that won’t raise the taxes on dividends quite as high, but companies do not appear to be taking chances.

More than 100 of them have declared special dividends in the fourth quarter, compared with the average of 31, according to Markit, a data provider that predicts at least 20 more will be announced by the end of the year.

The biggest beneficiaries at many of these companies will be the families and managers who run them.

A new report, also from Markit, shows that more than half the firms giving one-time payouts next month have inside ownership greater than 25 percent of the company’s shares. Of the 74 companies examined by Markit, an average of 30 percent of the shares were owned by insiders.

Las Vegas Sands said Monday that it will pay $2.75 a share, a total of $2.26 billion, next month. Roughly half the stock is owned by chief executive Sheldon Adelson and his wife.

“The cash flow of our current operations and the strength of our balance sheet have put us in the enviable position of both returning capital to our shareholders while at the same time staying true to our roots as a growth company,” Adelson said in a statement Monday.

Rather than adding a dividend, some companies are simply shifting their calendars by moving up payouts a few days earlier to catch the end of the year.

Last week, Wal-Mart rescheduled its dividend payout from Jan. 2 to Dec. 27 in order to avoid the tax increase. The Walton family owns about half the company’s stock.

Leggett & Platt, which makes components for bedding and furniture, made a similar announcement this month, saying it would also move its payout from January to December.