Todco

(THE)

set plans to sell 13 million shares held by parent

Transocean

(RIG) - Get Report

in a secondary offering.

Todco, a Houston-based drilling company, said the stock accounts for 22% of its outstanding shares. Morgan Stanley and Citigroup are acting as joint book-running managers, and Goldman Sachs is acting as co-manager.

The offering comes as Transocean continues to reduce its investment in Todco, which once was a wholly owned unit of the Houston-based oil services giant. A secondary offering earlier this fall brought Transocean $270 million while reducing its voting stake in Todco to 82%.

On Monday, Todco advanced 26 cents to $16.95, and Transocean added a penny to $16.91.