International Airlines Group, the holding company created by the merger of Spain's Iberia and British Airways, said Thursday it will launch an offer for the 54.15 percent of Spanish budget airline Vueling that IAG does not already own.

In a filing with Spain's CNMV stock market regulator, IAG said it has made an offer of 113 million euros ($144.13 million), or 7 euros per share, a premium of nearly 28 percent over the share price at the close of trading on Wednesday.

Trading of Vueling's shares was suspended after IAG said Wednesday it was considering a bid for full control of the airline. When trading resumed late in the day Thursday, Vueling's stock price jumped by 25 percent from 5.47 euros to 6.85 euros.

IAG's offer comes a day before the company publishes its results for the first nine months of 2012 and is expected to present its plans for restructuring Iberia.

The offer is expected to be finalized in the spring of 2013.

AIG plans to maintain the management of Vueling as an independent operator and to keep in place the company's management team, headed by Chairman Josep Pique, a former Spanish government minister, and CEO Alex Cruz.

In a statement, IAG's chief executive, Willie Walsh, hailed Vueling's leadership position at the Barcelona airport, as well as its European growth strategy and low cost base.

Vueling, based at Barcelona El Prat Airport, "has much to offer IAG," Walsh said, noting that the airline has boosted capacity significantly while also remaining profitable despite of Spain's lengthy economic downturn. EFE