(Adds Aeromexico reaction)

By Veronica Gomez Sparrowe

MEXICO CITY, Oct 3 (Reuters) - Mexican airline Mexicana said on Wednesday it offered to buy rival Aeromexico for $200 million, the highest amount so far for the struggling carrier in a bidding war that has attracted three groups.

Aeromexico shares AMEXICOA.MX jumped over 10 percent after the news and held much of those gains, closing up 15 centavos, or 7.54 percent, at 2.14 pesos, lower than Mexicana's offer as the bid is likely to come under anti-trust scrutiny.

Eduardo Perez Motta, head of Mexico's anti-monopoly commission, the CFC, warned that the offer may not be allowed.

"Who knows if we are going to approve it," he said. "For the moment, the figures do not give much hope that this will happen."

Mexicana is offering 2.19 pesos per Aeromexico share, topping last week's sweetened $160 million bid from the Saba family, one of the country's wealthiest, with interests in real estate, textiles and pharmaceuticals.

The offer will stand for 20 days once approved by Mexico's banking and securities commission. The bid also needs to be cleared by the country's anti-monopoly agency.

"Merging the two companies into one single airline group will allow them to become profitable," Mexicana's Chairman Gaston Azcarraga told a news conference.