An investor group led by NBC Universal and two private equity firms clinched a deal for the Weather Channel on Sunday after three weeks of negotiations.

Though the parties did not disclose the price, the buyers, NBC and the private equity firms Bain Capital and the Blackstone Group, will pay just under $3.5 billion, people briefed on the matter said.

That is less than the $5 billion that the Weather Channel’s parent, Landmark Communications, sought when it put the basic cable channel and related properties like weather.com up for sale in January.

In a sign of the weaker debt markets that have clamped down on large private equity deals, more than half of the price will be paid in equity, to be divided roughly equally among the three buyers, these people said.