Does the public relations department contribute to the reduction of annual marketing costs in public and private sectors?

Some of the main goals of public relations are to create, maintain, and protect the organization's reputation, enhance its prestige, and present a favorable image. Studies have shown that consumers often base their purchase decisions on a company's reputation, so public relations can have a definite impact on sales and revenue. Public relations can be an effective part of a company's overall marketing strategy. In the case of a for-profit company, public relations and marketing should be coordinated to be sure they are working to achieve the same objectives.

Another major public relations goal is to create good will for the organization. This involves such functions as employee relations, stockholder and investor relations, media relations, and community relations. Public relations may function to educate certain audiences about many things relevant to the organization—including the business in general, new legislation, and how to use a particular product—as well as to overcome misconceptions and prejudices. For example, a nonprofit organization may attempt to educate the public regarding a certain point of view, while trade associations may undertake educational programs regarding particular industries and their products and practices.

It all depends on the situation one is handling..........Crisis communication, aiming at damage control, may incur huge expenses.....for a long term return. Choice of messages, media selection and situation are the factors that determine the PR or the adspend. Usually, PR doesn't aim at cost reduction........commercial communication does! 

Yes public relations contribute to the mitigation of spending costs by broadcasting policy guidance in expenses and other institutions to improve the service and the creation of the so-called greater profits at the lowest cost plans

Public relations department is for sure contribute to reduce the marketing costs in both public & private sectors by communicating efficiently & effectively with dealers , suppliers , customers and even stakeholders.

I agree with the experts answers. Thank you.

Yes it is if you apply the right PR strategy and deliver by the right professional. The PR strategy should be developed based on the organization vision and mission. Hence its  PR activities should be tailored towards supporting the marketing activities such as positioning the brand in its PR activities.

Highly professional and innovative staff can help you save a lot. but as you said the "department" having huge department can cost you more than the annual marketing budget.