BRASILIA (Reuters) - Brazil’s five-party centrist coalition has united behind business-friendly presidential candidate Geraldo Alckmin, boosting the chances of a reformist winning the October election.

FILE PHOTO: Geraldo Alckmin of the Brazilian Social Democracy Party (PSDB), a pre-candidate for Brazil's presidential election, arrives on the a Mobility Forum of the National Association of Passenger Carriers on Rails, in Brasilia, Brazil July 18, 2018. REUTERS/Ueslei Marcelino

The businessman tipped to be Alckmin’s running mate, however, has declined. Josué Gomes, chief executive of Companhia de Tecidos Norte de Minas, the biggest textile group in Latin America, refused an invitation by the coalition.

Alckmin, a four-term governor of Sao Paulo, is seen by investors as the best choice to maintain belt-tightening policies to curb government spending and restore confidence in an economy struggling to recover from its worst recession.

Support from the centrist bloc made up of the Progressive Party (PP), Democrats (DEM), Solidarity (SD), Brazilian Republican Party (PRB) and the Party of the Republic (PR) was key to approval of fiscal reforms by President Michel Temer.

“We are convinced that the only way to pull Brazil out of the pit is to join forces,” congressman Paulo Pereira da Silva, leader of the Solidarity party, said at an event where the coalition formally announced its endorsement of Alckmin.

Alckmin’s new alliance comes at a crucial moment, as party conventions are underway that will determine the strongest candidates for the campaign that kicks of on Aug. 16 by adding free television and radio time and public funding.

With the center block in his camp, Alckmin will have 40 percent of the daily 12-minute television broadcast time for electoral propaganda, a vital prop for an uncharismatic candidate who is running fourth in current polling.

A survey by pollster Datafolha showed Alckmin had just 6 percent of voter support, behind the center-left populist Ciro Gomes, environmentalist Marina Silva, and front-runner Jair Bolsonaro, a far-right nationalist who has capitalized on voter anger with political corruption and leads with 17 percent.

With the country’s most influential politician - former president Luiz Inacio Lula da Silva - jailed, sidelined by a corruption conviction, the Oct. 7 election is the most uncertain in decades in Latin America’s largest nation.

Centrist support for Alckmin dealt a blow to Ciro Gomes, a former governor of Ceará state not related to the textile executive, who had courted the coalition.

With Lula behind bars, Gomes is emerging as the standard bearer of Brazil’s left and could make it to the second-round runoff in the election if he gets Lula’s endorsement and the backing of the Brazilian Socialist Party (PSB).

Front-runner Bolsonaro, a former army captain and apologist for Brazil’s 1970-1980s military dictatorship, has not been able to draw allies or find a running mate outside his small party.