Trinity Mirror this afternoon confirmed that the Birmingham Post is to become a weekly newspaper from 12 November while the Birmingham Mail will switch to overnight printing.

Around 82 jobs - 40 of them editorial roles - are under threat of redundancy as a result of the changes, which the company says it hopes to secure through voluntary means.

In addition, both Post editor Marc Reeves and Steve Dyson, editor of the Mail and sister weekly the Sunday Mercury, have decided to leave their posts, with Dave Brookes, editor of sister daily the Coventry Telegraph taking over as editor-in-chief of the three Birmingham titles.

The official announcement today from Trinity Mirror brings to an end weeks of debate and speculation about the titles since the company launched a consultation with staff, unions and advertisers at the end of August.

A statement from Trinity Mirror said the Birmingham Post would be "developed as a multimedia brand with a comprehensive 100-page minimum weekly print title".

It will offer in-depth coverage of business news with analysis while birminghampost.net will continue its daily breaking news and comment service.

Although publication of the daily print product will cease, outgoing editor Marc Reeves revealed on his blog that a daily digital version of the Post will be emailed to subscribers each morning.

Marc said that readers would be able to scan the contents on their screeens or phones - or even print it off and read it in the "old-fashioned" way if preferred.

In this afternoon's statement, Trinity said the Birmingham Mail will move to overnight production early in 2010.

The company is also proposing to streamline its editorial operations by introducing a new, two-step process, centred on what it calls 'smart templating' of pages.

This involves reporters writing into pre-determined story shapes and is intended to speed up the production of news pages, meaning the majority of production roles on the Post and Mail, Sunday Mercury and Coventry Telegraph are at risk of redundancy.

There will also be a reduction in the number of photographers in the Midlands and a small reduction of staff on Trinity Mirror's Midlands weekly titles.

The changes also place under threat 42 roles in transport, distribution and newspaper sales departments – they have come about due to a forecast £6m loss facing the Trinity Mirror Midlands division.

Managing director of BPM Media John Griffith said: "In reaching the decisions we are announcing today, we have taken great care to consider all the options and we have sought the views of our staff, advertisers and key contacts.

"We believe the changes we plan to introduce offer the best way forward for the business, to help us tackle the immediate issue of the forecast deficit and to set us up more effectively for the longer term."