Hallmark Cards Inc. announced Wednesday it plans to buy all outstanding shares of Crown Media Holdings Inc. and take the company private. Crown Media, in Studio City, is the owner and operator of cable channels Hallmark Channel and Hallmark Movies & Mysteries. Nearly 90 percent of Crown Media stock is owned by Hallmark Cards, the Kansas City greeting card and gift business. Hallmark will buy the remaining outstanding shares for $5.05 a share in cash. With such a high stake in Crown Media, Hallmark does not need shareholder or board approval to buy it out. In a letter dated Tuesday to the Crown Media board, Hallmark Chief Executive Donald J. Hall Jr. said the company will use Crown’s cable channels to strengthen the Hallmark brand and the link with Hallmark’s business. “Hallmark will be able to direct Crown’s business and make all of those decisions in light of what is best for Hallmark as a whole, without being constrained by public, minority stockholders at Crown,” Hall wrote in the letter. Additionally, Hallmark will see a cost savings by eliminating the reporting and other regulatory functions required of a public company, the letter said. Shares closed up 17 cents, or 3.5 percent, to $5.10 on the Nasdaq.