In the spirit of patent licensing season, HTC and Nokia signed a patent agreement, but this act has more implications for HTC than your normal licensing pact. This has practically put an end to HTC's ongoing patent infringement lawsuits, not to mention losing streak, filed against it by Nokia.
One could say that Nokia's legal tactics has finally born fruit. Nokia filed several patent lawsuits in different places across the world. This has the effect of spreading HTC's legal resources quite thin. Considering its own financial situation and the number of losses it already has, HTC probably couldn't afford to prolong the agonizing battle.
Some also speculate that the decision to finally give in is a sort of preemptive move considering that Nokia's mobile business has been purchased by Microsoft, which definitely has more muscle and money to throw around in patent litigation. Whether that may be true or not, HTC doesn't have much resources to spread around. The company is looking towards a comeback, with a heavier bent on marketing. It will definitely need the money for that and can do without the bad publicity of losing further cases here and abroad.
Rather fortunately for HTC, it is not entirely a stranger to licensing patents from Nokia. After all, it already licenses Nokia's standards-essential patents (SEP) and this new licensing agreement will just cover the rest of the portfolio. Of course, the details of the agreement are kept under a tight lid but, aside from paying Nokia's licensing fees, HTC will also be sharing its LTE patents. This makes one wonder if Nokia, divested of its mobile business, will have plans for using these in the near future.