Looking on the internet deeply has found these results:

in a conference is the most popular phrase on the web.

in a meeting 11,140,000 results on the web	in a conference 134,600,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
Two people can often easily share a copy in a meeting. This can save paper and staff time resources. 2. Do provide web site URL's instead of paper documents ... 2. take a meeting, to hold or participate in a meeting. Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, ... Mar 17, 2015 ... So, if someone says "he is at a meeting" the meaning is that he has gone to a meeting, and if someone says "he is in a meeting" the meaning is ... Meetings are sometimes held around conference tables. In a meeting, two or more people come together to discuss one or more topics, often in a formal setting.	Is going to appear in a conference In São Francisco this night. By letter you refuse to participate in a conference on Aryan physics. No, she's in a conference in Miami. been involved in a conference on constitutional questions arranged by the DTP party; I told you, they must be in a conference. Results of this study will be presented in a conference at the end of the year. And: 'FT's short term risk has been mitigated by the French government said S & P analyst Guy Deslondes in a conference call.

in a meeting

11,140,000 results on the web

in a conference

134,600,000 results on the web

More popular!

Two people can often easily share a copy in a meeting. This can save paper and staff time resources. 2. Do provide web site URL's instead of paper documents ...
Mar 17, 2015 ... So, if someone says "he is at a meeting" the meaning is that he has gone to a meeting, and if someone says "he is in a meeting" the meaning is ...
Meetings are sometimes held around conference tables. In a meeting, two or more people come together to discuss one or more topics, often in a formal setting.

Is going to appear in a conference In São Francisco this night.
By letter you refuse to participate in a conference on Aryan physics.
No, she's in a conference in Miami.
been involved in a conference on constitutional questions arranged by the DTP party;
I told you, they must be in a conference.
Results of this study will be presented in a conference at the end of the year.
And: 'FT's short term risk has been mitigated by the French government said S & P analyst Guy Deslondes in a conference call.