Fiona Hyslop highlighted the potential impact of the plans on local news broadcasting in a letter to Ofcom Scotland director Glenn Preston.
STV has announced plans to close its loss-making STV2 channel as part of a major three-year restructuring plan, with 59 jobs to go.
In the letter Ms Hyslop expressed “regret” at the loss of STV News Tonight, which aired on STV2, and said the move “diminishes the range of voices and perspectives available to audiences”.
She said the government was also concerned about “the potential effect of these developments on the quality of coverage of Scottish news received by audiences in Scotland”.
Ms Hyslop wrote: “The Scottish Government supports Ofcom’s view that plurality matters and an important aspect of achieving this is ensuring a diversity of viewpoints are available and consumed across and within the media.
“In view of the range of current and anticipated developments, there may be a case for reviewing the plurality and quality of news provision in Scotland at an appropriate point in the near future to ensure that audiences in Scotland have access to a continuing diversity of viewpoints and high-quality programmes.”
Ms Hyslop also sought assurances over the sale of STV2’s local TV licences to That’s Media.
She said: “I would welcome confirmation as to whether the prior consent of Ofcom was obtained in advance of the announcement of the planned transfer of the STV2 licences, which I understand is expected to take effect from 29 June.
“Secondly, I assume that the commercial terms agreed with That’s Media Group Ltd oblige them to fulfil the commitments in all five local digital television programme service licences in full, including those for local news (and the higher level of local news commitments for Glasgow and Edinburgh), and we would welcome confirmation from Ofcom that the proposed new holder is aware of these terms and that they are an appropriate licensee.”
An STV spokeswoman said: “The decision to close STV2 has been made on a commercial basis. STV is not proposing any changes to our Channel 3 licence commitments, with STV News continuing to provide uniquely local programmes across Scotland.
“The future changes to STV News announced last week will result in a more comprehensive news service from STV.
“We will continue to deliver high-quality broadcast news defined by its localness and invest in our digital news, thereby increasing choice for audiences across all platforms.”