Belgian workers have blocked the entrances to the company's large plants in Leuven and Jupille for a week and at Hoegaarden since Tuesday in protest at AB InBev's plan to cut a net 263 jobs out of its 2,700 Belgian workforce.
The company has two other small production sites in Belgium.
Mediated talks to end the action ended without success late on Thursday.
The company's Belgian unit said on Friday it had secured a court order to end the blockade at Leuven, but preferred for the time being to solve the issue through talks.
A union official said enforcement of the order could prompt a full strike. Such a strike could start very quickly because the unions have already fulfilled a requirement to seek reconciliation.
We have a very united front. A strike is a possibility, one union official said.
AB InBev shares, positive for most of the morning, had turned negative by early afternoon, moving down 0.4 percent at 35.5850 euros.
It looked like a short-term thing, but it's moving on now... On a group level it's small, but the fear is that it could go wider, beyond just Belgium, a trader said.
InBev Belgium, which has a 57 percent share of the Belgian beer market, said it risked running out of raw materials soon. Barrels and cases of beer were piling up.
AB InBev, which makes Budweiser, Stella Artois and Beck's, has said it could cut some 10 percent of its 8,000 strong workforce in western Europe due to falling beer markets.
The company sold 5.6 percent less of its beer in the region on a like-for-like basis in the first nine months of 2009, part of a general downward trend exacerbated by the economic crisis.
However, AB InBev's profit margin did expand in that period.
(Reporting by Philip Blenkinsop; Editing by Erica Billingham and Hans Peters)