Vulcan Materials has sued Martin Marietta in federal court, accusing the smaller gravel, sand and stone supplier of launching an illegal takeover attempt of Vulcan.

Vulcan, based in Birmingham, Ala., also on Wednesday strongly recommended that its shareholders not tender their stock to Martin Marietta, which announced a hostile bid for the company earlier this month.

Martin Marietta, based in Raleigh, N.C., has said it plans to take a stock offer directly to Vulcan shareholders after Vulcan cut off negotiations that started more than a year and a half ago.

Under the offer, valued at about $4.74 billion, Vulcan Materials Co. shareholders would get half a share of Martin Marietta Materials Inc. stock for each of their Vulcan shares. That offer valued Vulcan at $36.69 per share, a 9.4 percent premium, based on the stock's closing price Dec. 9, the last trading day before Martin Marietta's announcement.

Martin Marietta also said when it announced its bid that it had filed lawsuits in both Delaware Chancery Court and New Jersey state court to ensure Vulcan shareholders get a chance to consider its offer.