A general meeting of shareholders convened to consider a specific and unexpected thing — such as a takeover offer. To be contrasted with an annual general meeting, which a company must have each year, and at which institutional shareholders approve financial reports, confirm appointments of directors and officers, and small investors grandstand and throw bread rolls at the fatcats in the C-suite.
Occasionally you can have ordinary general meetings that for one reason or another are out of the ordinary — like the Teldar Paper example.
