USJ Co Ltd, the operator of a struggling Universal Studios theme park in Japan, said on Thursday it was being sold for $1.2 billion to a consortium led by Goldman Sachs.

The deal, the biggest such buyout in Japan in a year, was at a 28.5 percent premium to USJ's share price before the offer became public.

Customer numbers at the Osaka theme park, which features rides based on the movies Spiderman and Jurassic Park, have fallen in the midst of the global financial crisis and its shares have halved in value since 2007.

The new group would upgrade the theme park, including introducing new attractions and characters, the Goldman fund said in a statement.

It said the theme park faced tough growth prospects in tough times and as Japan's population ages.

Goldman, which holds about 40 percent of USJ through its fund, said private equity firm MBK Partners and Owl Creek Asset Management would take stakes in the privatized company.

Goldman said it would offer 50,000 yen per share to buy the remaining 60 percent of shares and rights by May 21, at a cost of 111.2 billion yen ($1.2 billion).

USJ said in a statement it had agreed to the deal.

That is a premium of 11,100 yen to the shares' closing price on Tuesday, the last closing price before Reuters reported an imminent tender offer on Wednesday, and just over half its record high price of 90,900 yen in May 2007, just after it listed.

At the completion of the deal, Goldman said it would own 61.2 percent of USJ, MBK 23.6 percent and Owl Creek would have 15.1 percent. USJ CEO Glenn Gumpel would have a 0.1 percent stake.

The new owners may consider mergers and acquisitions as a way for the company to expand into other leisure businesses and Asia markets outside Japan, Goldman said.

Osaka-based USJ listed on the Tokyo Stock Exchange in March 2007 but the global economic downturn has blunted Japan's usually voracious appetite for cartoon characters and other icons of cute.

Attendance at the park declined 5 percent during the nine months to the end of December from a year earlier, even as USJ stepped up efforts to bring in more visitors.

For the year ending this month, the company expects a net profit of 6 billion yen, down 11.3 percent from a year earlier.

The deal is the biggest buyout in Japan since Advantage Partners' $2.2 billion purchase of Tokyo Star Bank completed in March last year, Thomson Reuters data showed.

($1=95.99 Yen)

(Editing by Rodney Joyce)