Pandora Media’s effort to find a financial savior has sent it into the arms of John Malone’s Liberty Media with a $480 million investment agreement announced this morning.

Liberty-owned SiriusXM will buy convertible preferred stock equal to 19% of Pandora — with an agreement not to go above 31.5% unless the board approves in 18 months. The price would amount to $10.50 per share.

The investment gives SiriusXM the right to designate three members of Pandora’s nine-member board. One will be Chairman.

In conjunction with the deal, Pandora agreed to sell its Ticketfly ticketing business for $200 million to Eventbrite. The companies now have a commercial agreement that Pandora says will “substantially broaden the scale of its ticketing opportunities.”

The Ticketfly deal is due to close by the end of September.

The news sent Pandora shares up 6.4% to nearly $9.00. SiriusXM is basically flat.

“This strategic investment in Pandora represents a unique opportunity for SiriusXM to create value for its stockholders by investing in the leader in the ad-supported digital radio business, a space where SiriusXM does not play today,” the satellite radio company’s CEO, Jim Meyer, says.

The combination of a subscription satellite radio service and a mostly ad-supported streaming one provides “exciting opportunities for Pandora to accelerate its growth and increase value for Pandora and SiriusXM stockholders,” he adds.

Pandora CEO Tim Westergren calls the deal  a “very significant juncture” for the streaming radio company he co-founded in 2000.

With a “robust balance sheet,” he’ll have “the flexibility we need to attack what is becoming a larger and larger opportunity as digital music enters a new golden age.”

SiriusXM last year informally offered to pay about $3.4 billion, or $15 a share, for Pandora — which the board rejected. Pandora signaled in December that it had warned to the possibility of a deal.

But Pandora’s value diminished as it struggled to keep up with streamed music competitors including Amazon, Apple, Google, and Spotify. Pandora reported a $132.3 million net loss in Q1, up 14.9%, on revenues of $316.0 million, up 6.3%.

“I would buy Pandora if it were not $13” a share, Liberty Media CEO Greg Maffei said in March. “You want to sell it for $10? We probably would buy it. But they’re not selling it for $10.”

Private equity firm KKR agreed to invest $150 million, but Pandora put that on hold this week as it considered other opportunities. Verizon also kicked the tires.

Maffei says today that Liberty “has long recognized the strength of the Pandora brand and the opportunities in the ad-supported digital radio market. We are very supportive of SiriusXM’s strategic investment.”

PiperJaffray’s Stan Meyers says that although the deal is not “the full-takeout we once expected, it does meaningfully strengthen Pandora’s balance sheet, which has been weighing in on the stock and delivers a strategic partner that can help grow Pandora in the car.”