BERLIN — At an age when most folks are enjoying retirement, Leo Kirch is making a career comeback.

Actually, the 80-year-old former media tycoon, whose vast empire collapsed in 2002, never left the local industry but his presence remained cloaked.

The enigmatic Kirch, it turns out, is a secret shareholder in Swiss entertainment company Highlight Communications, parent of Germany’s most successful producer-distrib, Constantin Film, as well as the Swiss-based sports rights group Team, which manages the hugely popular UEFA Champions League soccer competition.

Not only has Kirch continued to profit from European soccer, he also saw returns from Constantin hits such as “Downfall” and “Perfume.”

Last month Kirch agreed to sell his 36.4% stake in Highlight to EM.Sport Media in a deal valued at e163 million ($230 million). In exchange, Kirch will get an 11.5% stake in EM.Sport and some $170 million in cash. Deal is subject to antitrust approval.

The swap will leave EM.Sport the largest Highlight shareholder and Kirch EM.Sport’s biggest shareholder.

An expected merger would create a sports rights and production powerhouse worth about $1 billion.

“The acquisition is a carefully planned step toward internationalization and rounding-off the value chain,” says EM.Sport topper Werner Klatten.

Observers see it as a master plan to rehabilitate Kirch’s legacy following the collapse of his media empire, which included terrestrial TV broadcast group ProSiebenSat1 and Premiere, the only nationwide pay TV platform.

Kirch has been trying to clear his name from the biggest bankruptcy in post-war Germany for five years.

Octogenarian looks likely to win substantial damages from Deutsche Bank, which he is suing for $2.1 billion for its part in the group’s demise.

Last year, Germany’s highest court ruled that Deutsche Bank and former topper Rolf Breuer were partially responsible for Kirch’s insolvency because Breuer violated client confidentiality in a 2002 interview in which he cast doubt on Kirch’s creditworthiness when his company had a $6 billion debt.

Ironically, the main reason for Kirch’s debt back then, Premiere, which was hemorrhaging more than $1 million a day, may play a key role in his comeback.

EM.Sport already does business with the now healthy Premiere — its live sports production division Plazamedia (a onetime Kirch asset) recently extended a deal with the paybox through 2013 and it also holds a 5% stake in Premiere’s satellite service Premiere Star.

Last week, the German Football League (DFL) agreed to give rights to top Bundesliga soccer to Kirch’s Sirius in return for a guaranteed $4.2 billion income over six years beginning in 2009.

Premiere relies on soccer to boost subscriber numbers — although bullish execs have said they won’t pay much for the rights if Sirius sells them elsewhere.

The deal will also bolster EM.Sport’s own free TV sports web DSF (which also used to belong to Kirch).

EM.Sport and Highlight’s focus on sports rights has fanned speculation Constantin Film could be sold off. Constantin has denied it, saying business is good and Highlight would have little reason to sell.

Says Klatten, “We are strengthening our position as an independent media company with the inclusion of the activities of Constantin Film.”

Not to mention that, like most of the assets in play, Constantin too once belonged to Kirch.