Grupo Mexicana de Aviacion SA, which filed for bankruptcy protection in August, may resume flights as a scaled-down company in December if creditors and unions accept a takeover proposal from investment firm PC Capital SAPI, a government official said.PC Capital, a Mexican private equity and investment banking firm, would offer a combination of debt, equity and cash for Mexicana, Humberto Trevino, deputy minister of transportation, said today in a phone interview. The airline would have 28 planes and would fly 17 international routes to the U.S. and Central America and fly seven domestic routes, he said.