The Business body is appearing at the Oireachtas Transport Committee alongside tourist groups, the IDA and Enterprise Ireland.
IBEC feels IAG is a good fit for Aer Lingus, and could boost Dublin's capacity as an international hub.
Both the IDA and Enterprise Ireland are seeking more information about long-term plans for Aer Lingus.
Mary-Rose Burke of IBEC told the committee that the sale of the former national carrier could have huge benefits.
“We see the proposed merger as potentially very beneficial for the company, for tourism, for inward investment and for the wider business community” he said.
“We acknowledge that there are legitimate concerns for particular regions; but we believe that these can be addressed, given sufficient goodwill and trust building” she added.
However the Irish Hotels Federation has expressed concerns about the loss of Aer Lingus' Heathrow slots.
Chief executive of the IHF is Tim Fenn.
“We support the recent commitment from the government to seek a permanent and cast-iron guarantee in respect of connectivity for Shannon, Cork and Dublin Airports” he said.
“The temporary five year arrangement proposed by IAG is entirely unacceptable – there needs to be a permanent commitment if any sale is to be considered by the government” he added.