Unfortunately news content is expensive to provide so your free options are extremely limited especially if your site is commercial in nature. This is a big reason why I developed All Headline News. Consider taking advantage of the free trial. Although not a free service, it's expensive to provide the content, bandwidth and servers and staff, it is very low cost and has a very nice feature set.
Moreover isn't free anymore and definetly not inexpensive but they do have a well developed product.
NewsKnowledge also offers headline content but it's not free. Also well developed and competent
Individual sources sometimes offer headline content but beware and carefully read the TOS almost all of them do not allow commercial use or placement of their content.
Here are some links for you
Also look at Business.com's lisings