Raleigh, N.C.-based Martin Marietta Materials approached Birmingham, Ala.-based Vulcan Materials Co., the nation’s top aggregate producer, with an unsolicited offer to take over the company with a stock-for-stock transaction.

If this hostile takeover were approved, it would create a U.S.-based company that, as of Dec. 9, had a combined market capitalization of $7.7 billion and a combined total enterprise value of $11.4 billion, according to Martin Marietta. The combined mineral reserves of both companies would be 28 billion tons.

Martin Marietta President and CEO Ward Nye, Aggregates Manager’s 2006 AggMan of the Year, says the combination of both companies “is a compelling opportunity for both companies’ shareholders, customers, employees, and the communities we serve.”

Nye notes that by bringing together what he calls “complementary assets,” it creates the opportunity to create a global aggregates leader.

Together, Vulcan and Martin Marietta expect to achieve cost synergies of $200 million to $250 million.

“We also intend to maintain the dividend of the combined company at Martin Marietta’s current rate of $1.60 per Martin Marietta share annually, or the equivalent of 80 cents per Vulcan share annually, based on the proposed exchange ratio,” Nye said in a written statement. “This dividend rate is 20 times Vulcan’s current level.”

The proposal, including the exchange offer is unanimously supported by Martin Marietta’s board of directors. Under the terms of the exchange offer, each outstanding share of Vulcan would be exchanged for 0.50 Martin Marietta shares.

The offer represents a premium for Vulcan shareholders of 15 percent to the average exchange ratio based on the closing share prices for Vulcan and Martin Marietta during the 10-day period ended Dec. 9 and 18 percent to the average exchange ratio based on the closing share prices for Vulcan and Marietta during the 30-day period ended Dec. 9, 2011.

Nye says Martin Marietta is bringing the proposal directly to Vulcan shareholders after the company stopped participating in private discussions toward a negotiated transaction, which began more than a year ago.