NEW YORK (TheStreet) -- Share prices across the dry-bulk shipping sector declined sharply Tuesday in the wake of Monday evening's third-quarter earnings report from DryShips (DRYS), the largest market-cap company in the industry.

Much of the weakness in marine-transport shares blew in on storms from the Baltic Dry Index, the shipping-rates gauge administered by the London-based Baltic Exchange, a ship broker. After posting strong gains last week, "the rapid firming ... appears to have flattened," noted Omar Nokta, an analyst with the boutique investment bank Dahlman Rose, in a note to clients.

The mean day rate for the biggest and traditionally most lucrative vessels, the enormous capesize ships so big they can't fit through the world's canals, dropped below $50,000, according to the Baltic Exchange.

Contributing to the sector's Tuesday woes was selling pressure across the commodities economy, from miners of base metals to producers of steel -- and, naturally, the shipping companies that move iron ore between mines and mills.

Leading the decliners Tuesday was DryShips, whose shares fell 7.6%, or 52 cents, to $6.37, one day after beating Wall Street expectations with a "clean quarter," in the words of one shipping-stock investor.

Some market players may have been looking for DryShips to announce Tuesday during its earnings conference call with analysts and investors that it had finally obtained the charter contracts it's been seeking for some of its new offshore drilling rigs. No such announcement occurred, however.

DryShips requires those fixtures in order to induce banks to loan it the $1 billion it still needs to pay for the ships, which are now being constructed at shipyards in South Korea.

In the conference call, DryShips' operating chief, Pankaj Khanna, also said that the company favors an IPO over a spin-out for its drill-ships business. It had previously been mulling both options.

Elsewhere, shares of Genko Shipping and Trading ( GNK - Get Report) lost 5.4% to finish the regular session at $13.70. The company is slated to report its quarterly results Tuesday evening.

The declines were similar in other Greek-based shipping names. Shares of Navios Maritime ( NM - Get Report) lost 5%, Paragon ( PRGN) retreated nearly 6% and Eagle Bulk ( EGLE - Get Report) declined by 4.8%.

Fairing a little better were shares of Diana Shipping ( DSX - Get Report), which fell by 1.6%, and Excel Maritime ( EXM), down about 4% on the day.

-- Written by Scott Eden in New York

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Scott Eden has covered business -- both large and small -- for more than a decade. Prior to joining, he worked as a features reporter for Dealmaker and Trader Monthly magazines. Before that, he wrote for the Chicago Reader, that city's weekly paper. Early in his career, he was a staff reporter at the Dow Jones News Service. His reporting has appeared in The Wall Street Journal, Men's Journal, the St. Petersburg (Fla.) Times, and the Believer magazine, among other publications. He's also the author of Touchdown Jesus (Simon & Schuster, 2005), a nonfiction book about Notre Dame football fans and the business and politics of big-time college sports. He has degrees from Notre Dame and Washington University in St. Louis.