"The Vueling board has a negative assessment of the takeover bid made by the bidder because of the compensation offered, and recommends that shareholders do not accept it," the airline said.
"This report was unanimously approved by members present," Vueling, which is Spain's second carrier after IAG's Iberia, said in a statement issued late Thursday to the Spanish stock market regulator, the CNMV.
IAG, which already holds 46 percent of Vueling, lodged a bid December 11 to take over all the stock.
The group, born from a merger between British Airways and Iberia, offered to pay €7 ($9.20) a share, valuing Vueling as a whole at €209 million ($274 million).
Shareholders welcomed Vueling's decision to spurn the offer sending its shares up 38 cents, or 4.84 percent, to €8.23 in morning trade.
Vueling's board said a greater integration with IAG would "bring advantages and opportunities" to the airline but stressed that the bid offered no premium to the current stock market price.
Industry analysts generally agreed that the airline's share value was "clearly higher" than the IAG offer, Vueling said.
Vueling shareholders are to give their verdict at an annual general meeting in March or April.
IAG is slashing 3,800 jobs at loss-making Iberia in an attempt to cut costs.
Iberia workers are striking this week in the second of three five-day strikes, with many of them accusing the British firm of ruining a key Spanish asset.