UPDATE 2-Votorantim may take control of Peru miner Milpo

(Recasts, adds comment from Milpo, regulators)

By Teresa Cespedes

LIMA, March 27 (Reuters) - Brazilian conglomerate Votorantim said on Thursday it will pay up to $422 million to boost its stake in Peruvian miner Milpo (MIL.LM), as it seeks to expand amid booming demand for metals.

If the offer is successful, Votorantim, the world's third-largest zinc producer, would own 51 percent of Milpo's circulating shares, in which case regulators said it would gain control of the company.

Mining companies have been consolidating in a thriving sector as strong global demand has boosted metals prices.

Milpo shares rose about 15 percent to 8.05 soles on Lima's stock exchange after privately held Votorantim launched the offer in a letter to Peru's securities regulator.

Milpo, a 60-year-old company that produces zinc, copper and lead, says it runs some of the lowest-cost mines in the world and has a large exploration team.

Votorantim offered to buy up to 147,151,328 Milpo shares at $2.87 -- about 8 soles -- each.

"This price represents a premium ... of 27 percent over the average price of the last 30 days," Votorantim said.

Votorantim said its offer is for "26.12 percent of shares in the market." It already owns 24.88 percent of Milpo's shares in circulation.

An official at Peru's securities regulator Conasev said "if a company has 50 percent plus one of the shares in circulation, it has control."

Votorantim said its offer will be good for 20 days and it has a letter of credit from JPMorgan to cover purchase of the shares.

"It's interesting to know that a partner that we already have is interested in the operation," said Juan Alberto Flores, a Milpo spokesman. "If the offer is a success, it would be looking for control because it's participation would be very strong."

($1 = 2.80 soles) (Additional reporting by Ricardo Serra and Terry Wade in Lima and Marcelo Teixeira in Sao Paulo; Editing by David Gregorio)