MEXICO CITY (Reuters) - Andres Manuel Lopez Obrador’s new chief of staff is a tycoon and former Olympic equestrian show-jumper whose gamble on Mexico’s leftist president-elect paid off politically, but who must now tread carefully to avoid conflicts of interest.

Alfonso Romo, top economic adviser and chief of staff nominee of Mexico's leftist presidential election front-runner, Andres Manuel Lopez Obrador, speaks during an interview in Mexico City, Mexico July 5, 2018. Picture taken July 5, 2018. REUTERS/Alexandre Meneghini

Once one of Mexico’s wealthiest men, Alfonso Romo slipped down the rich list as a series of high-stakes biotechnology investments backfired.

But the businessman was on the money with his full-throated support for Lopez Obrador, whose landslide victory on July 1 reshaped Mexico’s political landscape. Romo, 67, began backing the politician shortly before his failed 2012 presidential campaign. Now, the businessman is poised to be at the center of a government pledging bold steps in crime-fighting and corruption while considering changes to important business sectors.

Days before the election, Lopez Obrador tapped Romo to serve as chief of staff, which puts him in the cabinet when the new government takes office on Dec. 1. Romo will co-lead the economic team in the transition until then.

He said in an interview that he does not expect to find any conflicts that would prevent him from taking the post, but that he would step aside before he would sell any ventures.

Some political watchers still marvel at how the equestrian, who competed in the 1996 and 2000 Olympic Games, vaulted into the cabinet of Mexico’s first leftist president in decades.

So far, Romo has been a savvy choice for Lopez Obrador. His business credentials have helped defuse opposition from the private sector, long among the most formidable critics of the leftist politician.

“This was my job from January of last year,” Romo said, adding that he saw “not total acceptance, but a big part of the private sector understanding much better what we are proposing.”

Romo also helped Lopez Obrador gain traction in Mexico’s prosperous northern states, where he had struggled in previous campaigns.

As he transitions to government, Romo will have to navigate potential conflicts of interest between his political work and his business empire.

Grupo Plenus, where he serves as president of the board, has investments in biotechnology, education and financial services, among other fields. He is also honorary president of independent brokerage house Vector.

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Romo said potential conflicts were one of his main reservations about accepting the chief of staff job.

“I think I don’t have anything that hinders me, but I will be very cautious.... I don’t want to hurt Andres Manuel,” he said, adding that if he discovers issues that cannot be resolved, “I’ll leave.”

Amid its push to curb corruption, Mexico has stepped up rules around conflicts, said Rodrigo Montes de Oca, a research scholar at the Houston-based Baker Institute Mexico Center. Mexican law requires public servants to speak up when they have a conflict and recuse themselves if necessary.

The chief of staff’s broad purview makes it a particularly sensitive job, Montes de Oca added.

Romo stressed he thinks the issue is manageable but is reviewing the legal situation, noting he does not hold operational roles in his companies.

OBSTACLE BY OBSTACLE

Romo’s foray into politics caps off a career full of twists. He purchased cigarette maker Cigarrera La Moderna for $85 million in 1985. An end to tobacco price controls helped increase its value, he said, and he sold the company a decade later for $1.7 billion.

The business was a strong source of local employment, Romo said, noting that none of his tobacco fields were attacked during the Zapatista revolution of the 1990’s. “All of my businesses have always had a social component,” he said, explaining his kinship with Lopez Obrador.

He used proceeds from the tobacco company sale to fund Seminis, one of the largest producers of fruit and vegetable seeds. That firm became saddled with debts, and Romo took it off the market in 2003 before it was sold to agricultural technology giant Monsanto.

The series of transactions sparked a bitter legal battle with his father-in-law, Alejandro Garza, whose family launched bottler and retailer Fomento Economico Mexicano. The controversy soured Romo’s relationships with some businessmen in the industrial northern city of Monterrey, according to local media.

Romo said the feud was a minor contractual dispute and denied reports of falling out with the city’s industrialists.

“I get along marvelously with all the businessmen,” he said.

Along the way, Romo dabbled in politics, supporting President Vicente Fox of the conservative National Action Party as he ended more than seven decades of single-party rule in Mexico.

In 2011, he met Lopez Obrador, then mounting his second campaign for the presidency, through Dante Delgado, a political organizer, said Abel Hibert, a longtime business partner and fellow adviser to Lopez Obrador. Romo was instantly taken by the leftist, Hibert recalled.

Romo had some involvement in Lopez Obrador’s 2012 campaign, but he intensified his efforts for this year’s bid.

His most critical campaign task was bringing businessmen on board. Lopez Obrador’s pledges to review energy contracts and opposition to a $13 billion new airport for the capital spooked many business leaders.

A key milestone came when the Consejo Mexicano de Negocios, a group comprising some of the country’s largest companies, held a friendly meeting with the leftist shortly before the election, Romo said.

“The fact that (Romo) went out there and talked about who the real Lopez Obrador was, was a major factor in getting a lot of the business leaders in Mexico to be either neutral or on his side,” said James Jones, a former U.S. ambassador to Mexico who has known Romo since the 1990’s.

Romo’s influence can also be seen in Lopez Obrador’s more centrist platform, particularly with regards to private investment, Hibert said.

With the election behind him, Romo is eager to return to showjumping, which he put on hold a few months before the vote. He sees ample parallels between the sport and his new vocation.

In equestrian competitions, “one must go obstacle by obstacle… One must have patience,” he said. “Politics is the same.”