By Aishwarya Venugopal and Rishika Sadam

(Reuters) - Time Inc (TIME.N) said on Friday it would not sell itself but pursue a strategic plan to boost growth, sending its shares tumbling nearly 19 percent.

The decision ends months of speculation about a potential buyout and brings into focus the company's efforts to revitalize its stagnating revenue.

"The company is definitely not putting itself for sale. The focus now is to execute on our plan," Chief Executive Rich Battista told Reuters in an interview.

The publisher of Sports Illustrated and People magazines said the strategic plan included revamping its cost structure and focusing on its digital business.

The company, like its peers in the publishing industry, has been struggling amid a relentless decline in the print media as circulation shrinks and advertisers shift to digital platforms.

Time Inc's sales have fallen in at least eight of the last nine quarters as growth in its digital business fails to offset declines in the print business.

The company said in a statement that it had not initiated a sale process, but the board evaluated expressions of interest with the help of external advisers.

"Of course, if there is ever another expression of interest that is credible ... we have to evaluate it," Battista added.

The Wall Street Journal reported in December that the publisher had tapped Morgan Stanley (MS.N) and Bank of America Corp (BAC.N) to help field takeover or partnership interest.

U.S. media group Meredith Corp (MDP.N) made a preliminary offer that fell short of Time Inc's price expectation, Reuters reported earlier this month.

While Time Inc was seeking more than $20 per share, Meredith had made a preliminary offer with a price range that valued it below that level, the report said, citing people familiar with the matter.

Battista declined to give specific details on the offers received by the company.

Time Inc's shares were trading at $15.00, down 18 percent.

The company is scheduled to report first-quarter results on May 10.