A quick response is the following:

-Depending on the departmental policy how the information is classified and disclosed

-Privacy law of that country also need to be considered,

Thanks for initiating discussion with prompt and nice reply. Certainly, departmental policies can restrict sharing of information.

No doubt policy, but no one wants to be involved in any controversy raised by any information shared

One very simple explanation - public sector organizations usually have tendencies to secrecy, not sharing enough information, even notifying that to much information and transparency have negative consequences - After a number research and project I have worked concerning transparency and accountability of the government I can conclude that this is a process of evolution -  and usually there is strong correlation among  GDP growth, level of corruption, level of public debt/deficit, history of democracy on one side --- and sharing information and transparency on other...,  

The Asian Development Bank is a regional development bank owned by 67 member countries, of which 48 are from within Asia and the Pacific and 19 from outside. In 2011, it revised its Public Communications Policy, the full text of which is at https://www.adb.org/documents/pcp-2011 in about 20 languages.

Advancing a practice of presumption in favor of disclosure, ADB's Public Communications Policy promotes improved access to information about ADB operations for better development effectiveness. The policy enhances greater transparency and accountability by enabling ADB's stakeholders—especially people affected by development activities—to better participate in the decisions that affect them.

to avoid from any controversy public sector organisationscant share informations without permission/ through proper channel. 

@ Mushtaq Ahmad, Thanks for responding.  You have put an interesting point. I do agree, it is about taking responsibility. So, no org wants to indulge.

@ Borce Trenovski, Thanks for sharing you experience. I do agree with your view point but transparency cannot be brought unless and until information is shared?

@ Olivier Serrat, Thanks for sharing useful info about ADB

@Ben Levin, Thanks for nice contribution. Information production and information sharing are not two sides of the same coin?

It is noticed that lately, governmental organizations have more cooperation with other partners and better knowledge sharing than before.

Information capable of been misused against a country are usually protected. But most times some information are hidden because of lack of transparency in their dealings.

Question: Government departments (Public sector organizations) often do not share information even with peer organizations of the same country. The fact is, all these organizations are paid from exchequer.  The question therefore arises, why they do so? Please share your knowledge and experience. Thanks

Response:  Public Sectors are wholly owned by the public, led by the state or government of the day. Several information are considered classified/official secret information that are not accessible by public for several reasons especially when such information is construed to have either link to state security, stability or a threat to peace and harmony of such country. Such Information may be subjected to released years when it became clear that it does not threat such security again. This has been normal practice in the US, UK and other developed nations. In developing nations, the Act was inherited from the Colonial rulers at first to protect the interest of occupiers but later after independence, these new leaders that become the leaders of developing nations retained the Act for their self-interest. This has since become part of their domestic laws and was meant to keep their policy and secret out of reach of their enemies, may it be member of the public or opposition rival.  In Malaysia it is fall under the so called OFFICIAL SECRETS ACT 1972.  In UK: The first Official Secrets Act was enacted in 1889. This was replaced by the Official Secrets Act 1911. America's 'Official Secrets Act  1917 (Freedom of the Press Foundation on the Espionage Act of 1917). In Nigeria, The Official Secrets Act 1962 No. 29 (Chapter O3 of the Laws of the Federation of Nigeria 2004) is one example of an obsolete Nigerian legislation. It is a potent instrument for perpetrating the culture of secrecy in governance, which is blatantly against the right the right to know or the freedom of information. Australia has Part VII of the Crimes Act 1914 (Commonwealth), entitled Official Secrets and Unlawful Soundings.

In short, there are outcries at this new age to repeal the so call classified information, and number of countries has taken decisive action to do so amend it instead. In the Republic of Ireland, the Official Secrets Act, 1963 repealed previous British legislation of 1911 and 1920. In country like Malaysia and Nigeria, The act has been controversial for its use to silence dissent and stifling anti-corruption activities. I believe it is the time for public to fully access to government information in full so that there will not be hidden heaven for corrupt and tranny leaders to move freely.

Because the political powers fear the judgment of the people. Making public the expenditures, it can expose the governements to criticism on the wisely and necessity of the expenses themselves. Today, a little anywhere in the world, we live in an era of unprecedented favoritism and corruption. So it is necessary to obscure the information on public spending.

@Mahfuz Judeh,

Thanks for sharing your opinion.

@Chukwuebuka Egbuna,

Thanks for contribution.  I endorse you statement, “information are hidden because of lack of transparency in their dealings”.

@Abdullahi AYOADE Ahmad,

Hello thank you very much for a detailed reply. I agree, it is time to revisit the Acts and Policies of the past.

@Leonardo Cannizzaro,

Thanks for nice contribution. Yes, it is true to avoid criticism some public organizations may prefer to keep hidden their information collected with tax payers money.

I think that has much got to do with what kind of information is involved

Because of the nature of the information with which they have been entrusted, employees of public sector agencies are often prohibited by policy or statute from releasing information to outside entities. There is generally a mechanism to officially request information from the government (FOIA among others); however, it is a lengthy process designed to prevent sensitive, classified, evidentiary or otherwise protected information from being inappropriately released.  Those found in violation of the above stated policies/statutes face serious consequences, from administrative to criminal.  This breeds a "culture" of caution.

@Kevin J Donovan,

Thanks for responding and sharing quite valuable input. You concluded very nicely, This breeds a "culture" of caution. Much appreciated.

It all depends. They do provide data to many govt depts. If someone/some dept requests some non-sensitive info/data and they follow the prescribed procedure, they get it. Public Sector Institutes do make some of that kind of information publicly available too. A "need-to-know" factor apply to other data. This factor works where essentially needed. I am unsure about other govt departments but these org have rules to follow for provision of info/data.

My two cents!!