* Marken creditors hire Rothschild -sources

* Options may be new equity, debt restructuring -sources

By Simon Meads and Isabell Witt

LONDON, Feb 10 (Reuters) - Private equity group Apax is preparing for a tussle with lenders over British medical courier Marken, which it bought in a 2009 deal that paved the way for a resurgence in buyouts, people familiar with the situation said.

The buyouts group, which agreed to buy Orange Switzerland from France Telecom in December, has hired Houlihan Lokey to advise it on its options for the company that ships vaccines and blood from clinical trials around the world.

Those options could include restructuring the existing debt, injecting new capital, a sale of the company, or ceding a stake to lenders, some of the people said.

Apax's 975 million pounds ($1.5 billion) deal for Marken in December 2009 helped kick-start private equity M&A after a torrid year for deal activity following the collapse of Lehman Brothers.

In an unusually daring move, Apax swooped on the company after little direct contact with the group itself, trumping a bid by rival buyouts firm Hellman & Friedman with an all-equity offer.

Lloyds Banking Group later underwrote a 365 million pounds debt package, according to Thomson Reuters LPC data, the largest sponsor financing and the largest sole bank underwrite of 2009.

Marken's creditors, which include Lloyds and other investors, have hired Rothschild, sources said, as they prepare for a potentially bruising battle.

Financial figures soon to be published to lenders are expected to show the company breached the terms of its debt at the end of December.

Marken has seen its performance deteriorate significantly since Apax took over due to competition from other logistics groups and lower levels of research and development from large pharma groups, two of the people said.

Apax has been active around the world buying businesses in the last year. It recently completed its purchase of U.S. medical devices business Kinetic Concepts and bought the Golden Jaguar restaurant chain in China earlier in the year.

The firm is in the middle of raising a new 9 billion euro ($12 billion) buyouts fund, people have previously said.

Apax and Lloyds declined to comment.

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