RALEIGH, N.C.  – Amazon.com has pulled the plug on commissions for North Carolina Web sites that make referrals to the online retailer because a new tax could soon be enacted.

Seattle-based Amazon said it wrote to Web site operators, telling them the commission program will end after Friday.

Web sites that post links to the company about its products have received up to a 15 percent cut on sales.

But the Legislature is considering a way to collect sales taxes on these so-called “click-through” transactions. Amazon spokeswoman Patty Smith said the company believes the tax collection would be unconstitutional and decided to end the commissions because the change in the law could occur any day now.

House and Senate negotiators are still working on a final tax plan.